There are two specific limitations to a true 10 inch tablet.
1. The versions of Android prior to 3.0 have issues beyond 800x480. A true 10 inch would need 1280 or 1152 capability. This would make a true 10 in impossible in today's offering for Android Tablets
2. The cost of the screen is dramatically different the larger the touch screen and larger resistive screens like found on the 7 inch. And Apple has almost cornered the market for 10" capacitive screens.
These two create a real problem for you.
Thus, it would be difficult to purchase any unit right now at $200-250 which is a true 10 inch. There will be 10 inch screens, but not right now. And it would be closer to $300+
I am correcting myself, you can get a 10 inch such as Zenithink which uses 2.1 and the screen output is 1024x600. It is my understanding 2.1/2.2 can do this higher resolution. It is not the same as the resolution of the IPad. Only 3.0 will exceed that resolution. btw: The unit referenced is $220. But I have no idea as to quality and capability.
then i wait there are good multi touch screen tablets avaible but that is all win7 and big like salad plade i dont like them and costs too much nearly 450$ - 500$ i just want really good multi touch and high stand by time my friend buy 7 inc tablet that is terrible...
I am sure 10" 12" 14" tablets will follow-up. I look at my two 10.1" netbook and my 14" 16x9 laptop you can do more on 14" and I sure the cost will raise up. 15.6 and 17.3 would be overkill and I am sure those sizes will come out one day in tablet. If you on a crowded subway car in NYC a 7" tablet is more ideal than 10.1".