An iPad 3 -- not likely.
An AppleTV with the same hardware and new software ... yes, that's quite possible.
Of course, I don't have an insider knowledge of this, but this much is pretty solid: Apple usually has its holiday lineup in place by the end of September. They don't tend to make new product announcements (other than maybe very minor "bumps) any later than that.
We *already know for a fact* that iOS 5 is coming out in September, and we *believe pretty strongly* that a new iPhone model (and presumably a new iPod Touch, again a very safe bet) will be coming out around the same time.
We *know for a fact* that iCloud services will commence in the early fall (probably, again, September), and we *think* that the Mac Pro will get a VERY long overdue refresh about the same time.
There are also *rumours* of a redesigned MacBook Pro (thinner, more Air-like) and MacBook (ditto) coming out soon as well. And who knows, Apple could spring another complete surprise on us, an entirely new product like the long-imagined-by-analysts actual HDTV with Apple branding. We're also heard rumblings about an iWork '12.
This is, when you look at it and just sticking to the known and highly-likely items, already a lot of stuff, and iOS 5 should make even existing models like the iPad 2 "feel" newer -- so I'm inclined to believe that the iPad 2 we have now is the iPad that will be on shelves in December.
But the bottom line is: if it hasn't shown up by 30-Sept, it's most likely not on for this year.