When reporting keyboard experiences, please clarify where you are trying keyboard input and with what XBMC build. Neohusky's example is a good start.
I was able to try an Apple keyboard recently (thanks David), and my results are
YouTube(frontrow): Arrows(Yes), Esc(Yes), Return(Yes), TextEntry(No)
XBMC-4/2: Arrows(Yes), Esc(Yes), Return(Yes), TextEntry(Yes)
So I get the same "a only works" behavior in lowtide, but all keys and key combinations (caps, symbols) work as expected when for example adding a source in XBMC.
According to http://www.youtube.com/watch?v=RIvaRD-Ugis
keyboard text input should also work in frontrow (i.e. outside of XBMC), but I don't know if this version made it to the awkwardtv repo http://apt.awkwardtv.org/Packages
. Even though repo's date is later than the video announcement, I couldn't make it work. Anyone successful?
Edit: I received the following feedback from Matthias:
"Apple changed the way text is entered from 4.1 to 4.2.1, and TomCool updated hid-support to handle that.
I've submitted the latest version of hid-support to the BigBoss repository, as I'm using it for other iPhone projects. It should be available soon and will have the version 0.1.0-1"
And a quick google search shows that it should be available already:
So I'm hoping fixing keyboard input in lowtide under 4.2.1 will be as simple as "apt-get update" and "apt-get upgrade". I can't test until tonight though.