Nah. I wish it did that. But no, it replaces the hildon-input-method vkb (virtual keyboard) with this hildon-input-method vkb. And hildon isn't currently coded to support using different vkbs (virtual keyboards) in different modes.

This project is, well, very very dead. However, there's been talk of portrait-izing all of Hildon in some other threads - the only thing is, right now Qt on Maemo 5 has a horrible segfault-ing bug whenever a Qt app is launched while hildon is in portrait mode. So that's not going to hit mainstream use until that's fixed.