Apple Inc. (NASDAQ: AAPL) Apple has sent out media invitations for what's expected to be an iPad-related event to be held next week in San Francisco, California.

The event will be held March 7 at the Yerba Buena Center for the Arts Theater, where previous iPad models were unveiled. The invitation has an image of an iPad and has a tag line: "We have something you really have to see. And touch."

The iPad continues to be the most popular tablet in the market -- but its slice of the pie has decreased from 90% to under 70% and the game has changed in the past few months. Samsung, which has 5, 7 and 10 inch tablets in the market, is now the world's second largest tablet vendor.

Amazon has launched a 7-inch tablet that's available for a mind-blowing $199. Although the Kindle Fire doesn't have superior specs (just an 8 GB storage capacity, 1 GHz dual-core processor, has no cameras), the new tablet is seen as a vulnerable alternative or threat to the iPad given it's 60% cheaper than the iPad and it's backed by Amazon's cloud infrastructure and deep array of digital content.

Since Apple does not confirm any details about a new device until it is launched.

Hence, the purported specs of the iPad 3 will remain as rumors -- and thus the likelihood that they won't materialize -- until March 7.

Here are the top 10 rumored features:

Quad-core processor. ASUS already unveiled a tablet that runs on the NVIDIA Tegra 3 quad-core processor. There have been reports that the next iPad would have a quad-core A6 processor, succeeding the dual-core A5 processor used in the iPad 2. The quad-core processor should improve performance of the Apple device while preserving battery life. CNBC says its sources have confirmed that the iPad 3 would have a quad-core chip.

Virtual Assistant. Siri, the voice controlled voice assistant, is the major draw of the iPhone 4S. Fans would be disappointed if the iPad 3 won't have Siri, a voice-recognition system that turns the device into a hands-free personal assistant. Siri would increase the functionality of the tablet. The iPhone 4S with its dual core A5 processor is powerful enough to run Siri, which means that the iPad 2, which has similar specs, could run Siri right now. Hence, iPad 3 should have a tuned up version of Siri, which is currently in beta mode. Imagine if you could use Siri with your iPad to say, "Open Angry Birds, pull sling shot to maximum angle, move to 45 degree angle and let go."

Radical Design. The iPhone 4S showed that Apple is willing to recycle a successful hardware design. The iPhone 4S launched last October has an upgraded processor, camera, software, and features as virtual assistant, but had the same design as the fourth-generation iPhone. The iPad 2 had minor changes (thinner body and tapered edges) to the first iPad. Given that Steve Jobs had tasked Apple engineers to focus on design and aesthetics, it will be more likely that the iPad 3 won't do an iPhone 4S. With 4G, a quad-core processor, and better battery life, the iPad 3 might be bulkier than the iPad 2. But Apple will likely do some aesthetic changes to make the iPad 3 more attractive than the previous.

Two Models. Amazon has launched a 7-inch tablet that's available for only $199. Yes, the Amazon Fire Kindle priced less than half of the $499 entry-level iPad 2. According to reports, the new batch of iPads will include a more affordable iPad to take on the new Amazon tablet. Android, BlackBerry and webOS tablets haven't been able to gain ground against the iPad because of the ecosystem, apps and features provided by Apple and its stores. Although it doesn't' have superior specs, the Kindle Fire is getting a boost from Amazon's cloud infrastructure and deep array of digital content.

7-inch screen. Samsung offers tablets with 10.1- and 7.7-inch displays. Given that some people find the 9.7-inch-screened iPad too bulky, it is possible that Apple would have a smaller version of the iPad. For months, there have been reports that Apple is preparing an iPad Mini, a smaller and cheaper version of the iPad, in order to fend off the Kindle Fire. While its Macs have multiple models, Apple has been following a "one new model a year" rule for its mobile devices. So will Apple's Tim Cook unveil two new iPads? Unlikely, but not impossible.

No home button. Note that the March 7 media invite doesn't show a home screen. Samsung and Google unveiled last year a smartphone that has no physical buttons, the Galaxy Nexus. The "We have something you really have to see. And touch." In the invite have some suggesting that users would have to touch the iPad instead of pushing the home button to do basic functions. Of course, with the iPad 2 you can pinch with four fingers in order to show the home screen while in an app. But not everyone uses gestures to switch between apps. Is Apple really ready to get rid of the home button?

4G Capability. Samsung, HTC and Motorola have already released 4G-ready smartphones. And those devices using Long Term Evolution technology will likely extend to tablets. Apple will likely not want to be left behind by releasing a 4G version of the iPad 3. Remember that Samsung Galaxy S 2 ad that criticized the iPhone 4S as not even in 4G? The iPad 3 has to be in 4G. Apple used to be the king of innovation so it shouldn't be left behind.

Fresh retina display. The talks about a retina display first reared its head with the previous iPad 2 but this did not materialize. Now, iPad 3 is expected to arrive with a retina display, or at least a screen with double the resolution of the iPad 2, at 2048 pixels by 1536 pixels.

3-D features. Toshiba has already unveiled the world's first glasses-free 3D laptop, which uses a lenticular screen and integrated webcam. And LG Electronics has already released the LG Optimus 3D, which claims to offer "the world's first 3D experience on a smartphone. Apple filed a patent application related to 3D picture taking to the US Patent and Trademark Office later in March, according to an AppleInsider report. The filing described a system that would be capable of capturing, processing and rendering 3D images with the additional dual-camera hardware. So rumors that Apple would be incorporating a 3D-glasses-free feature on its new tablet appear to have credibility. But 3D technology on mobile devices is certainly in its infancy, making it unlikely that Apple engineers will add 3D features on the iPad 3.

Pricing. Apple rarely gives a price drop for new models. In fact, rumors say that the iPad 3 would be slightly pricier than the $499 entry level price of the iPad 2 last year. When the iPad 3 is released though, old models are expected to have a steep price drop. Expect the iPad 2 to be cheaper by $100.