There's always some sort of wild speculation floating around about what to expect next from Apple. But, there also comes a point in time where the rumors start to validate each other and reach a critical mass that indicates there may be more than a little truth to them. We've reached that stage with the Apple iPad 3 rumor mill.

Various reports suggest that Apple will unveil the next generation iPad in March. Depending on the source, Apple may hold an event during the first week of March (or even the last week of February) to reveal details of the iPad 3, and the device itself could be available that same day, or shortly thereafter.

Assuming the rumors are correct and a new iPad is imminent, the next question that comes to mind is what we can expect from such a device. Will it be an incremental evolution like the iPad 2 was over the original iPad, or will Apple truly raise the bar and make the iPad 3 a game-changing device for the tablet market?

Here are some features and capabilities the next iPad should have in order to take things to the next level:

1. Retina Display

The iPad 2 display is nice, but it's no Retina. With a resolution of 1024 x 768 on a 9.7-inch display, the iPad 2 has a PPI of 132. At 326 PPI the Retina display of the iPhone 4 and iPhone 4S is nearly two and a half times better.

Even a small improvement would make a lot of difference. Images and text on the Samsung Galaxy Tab 7.0 Plus--with a resolution of 600 x 1024 and a PPI of 169--appear clearer and crisper than on the iPad 2. If the iPad 3 can get the PPI even to 200 or higher it will be a significant improvement.

2. Better Camera

It was very exciting when the iPad 2 came along with front and rear-facing cameras. Everywhere I go I see people capturing images and recording video with their iPad 2. Let's face it, though, the iPad 2 camera sucks. Not capturing the moment at all is possibly better than the grainy quality of the iPad 2 camera.

I think it is a bit much to expect an iPad 3 to include Lytro's light field camera technology, which rumors suggest may be included with the iPhone 5. But, almost anything would be better than the cameras in the iPad 2. The rear camera can capture HD video, but only at 720p. The front camera is only VGA quality--on par with the Sony Mavica camera I had in 1999.

3. 1080p Recording / Playback

Combining those first two things together yields a third--1080p recording and playback. It seems that people like to use the iPad both as a means of consuming video content, and as a means of capturing video of important events. It would be nice to be able to record, and play that video in full HD.

4. 4G / LTE

3G is so 2010. There is speculation that the new iPad will include 4G / LTE wireless connectivity. While 4G networks are not as widely available yet as their 3G predecessors, it would be silly to continue developing devices that embrace yesterday's technology rather than embracing the future.

4G data speeds are significantly faster than 3G, which is important for a mobile device designed to consume data. Recent surveys have found peak download speeds of nearly 40Mbps for 4G, and sustained bandwidth that averages five times faster than 3G. The down side, though, is that 4G eats battery power faster, so Apple would need to boost battery capacity to maintain the same endurance, and that would add weight to the tablet.

5. Bring on Siri

Siri is uniquely useful on a smartphone, but since the launch of the iPhone 4S it has been assumed that the next-generation iPad would also include the virtual personal assistant. It would be just as nice to be able to ask Siri to schedule an appointment, check the weather, or get the latest stock market figures on an iPad as it is on an iPhone.

In fact, it would be nice if Apple would expand the capabilities of Siri to integrate with more of iOS. Apple could make Siri more functional by allowing you to tell Siri to take a picture.

Even better, Apple should let you designate the default app for iOS to use for certain functions. For example, I should be able to designat Garmin StreetPilot as my GPS / mapping app, or WeatherBug as my weather app of choice, and when I ask Siri for directions or weather information it should use my chosen apps instead of the iOS defaults.

6. Economy iPads

While it won't impact the iPad 3 itself, Apple can shake up the tablet market by offering some different options at bargain prices.

When the iPad 2 came out, Apple reduced the price of the original iPad to clearance out inventory. I expect Apple will do something similar for the iPad 2 when the iPad 3 comes out, but Apple could stir things up even more by not just clearancing the iPad 2, but continuing to offer it at the discounted price as an economy model of the tablet, just as it is continuing to produce the iPhone 4 as an econo-smartphone option alongside the iPhone 4S.

There also continue to be rumors that Apple is working on a smaller 7 or 8-inch model. If Apple were to come out with a 7-inch model of the iPad and price it aggressively in the sub-$300 range, it might take the wind out the sails of the Kindle Fire, and present a significant challenge for tablets like the BlackBerry PlayBook or Samsung Galaxy Tab that cost as much as the larger iPad.

Of course, it is also possible that all of the rumors and speculation are wrong, and Apple won't launch a next generation iPad until late 2012 sometime. Who knows? Whenever the iPad 3 comes along, though, I will keep my fingers crossed that these features and capabilities will be included.