It looks like that the next generation of Toshiba Android tablet and the successor of Toshiba Thrive is already in making. Toshiba has not yet made any announcement of Toshiba Thrive successor or any new tablet from them.
Toshiba latest unnamed product Thrive with codename Tostab06 is under development and was spotted on the official site of Antutu benchmark. The tablet is not yet announced. The AT 700 tablet will be a slim 10.1 inches tablet and it will come with a dual core processor clocked at 1.4 Ghz with Tegra 3 chipset. These are the same specifications seen on the Transformer Prime by Asus.
Reported that the Android version on the Toshiba Thrive Tostab06 would be Android 3.2 Honeycomb, but one would have expected it to be with Android Ice Cream Sandwich. Anyways, the ICS 4.0 update will not take much time to come for it.
There is no announcement from Toshiba when this tablet will be launched and we can expect that this tablet will be announced during the Mobile World Congress to be held in February last week of 2012.