Yep....
I think you're making one of the best guesses here, so far. Exactly my line of thought too, after everything I've read.
It looks like any tablet they announce won't even be shipping until the end of March or early April at the earliest (given rumors about having to add another process to strengthen the glass, etc. etc.), so they'll have to have other items to announce simultaneously, so at least one of them can be purchased soon after the event. But it's not SO far away that they wouldn't announce it by the end of January either.
I think the 8GB version of the 3GS is likely, since it's easy for them to offer... almost a "Why not?" item they can throw in.
Adding a camera to the iPod touch is another item they could easily do, to provide an easy revision bump for the device. After the big Xmas sales, they're probably in a good position to update it too. (No huge inventories of existing stock lying around in warehouses.)
As for selling 10 million tablets? I think it's very possible, if you figure they'll probably sell it for one price, stand-alone, and optionally at a big discount if you sign up for a 2 year 3G cellular data plan for it, through whatever carrier they partner with. (Quite possibly Verizon, since it might explain all those partnership rumors AND still explain why Verizon is even an option, given their anti-iPhone stance in the past. Maybe the iPhone will go to T-Mobile instead?)
My guess is:
-tablet
-8GB 3GS
-iPod touch with camera
Interesting that it is said that Apple is projecting to sell 10 million units when it will be just an oversized iPhone. The only way they could sell that many is if it was sold at a very low price which Alex Albrecht has rumored on Diggnation.
