A source is claiming that the iPad 3 will be announced on March 7. That date is a Wednesday this year which that particular day of the week falls in line with other product announcements by Apple. That week also falls inline with earlier reports just a few days ago from another source.
So, on March 7 this year we should hear more about the iPad 3 and perhaps be given a release date of the week after earliest.
The rumours of what will be included have more or less been the same such as a Retina display with a resolution of 2048x1536 pixels. Also an Apple A6 quad-core chip was also mentioned although some believe Apple wont go for quad-core but will instead, choose another dual-core with far better performance than the A5. A new rumour hints at 4G being included although with 4G there's still battery life to consider. It might be too early for that to arrive in this model. Expect it to be a "world iPad" though with both CDMA and GSM versions combined in to the single unit.
Nobody out of Apple will know for sure what the new iPad will have, but it's fairly easy to predict that the specs will be bettered this time around which means the higher res screen, faster CPU and better cameras are likely. We don't expect to see anything too radical though.