Ahh, well, if it's been over a year, then, getting it fixed under warranty isn't going to happen. :'( Unless it's been really close to a year. Sometimes if you send a really well written email, or, talk to a really good CSR, they can push you past the limit on your warranty. I havehad that work for me as well.
If the trackpad works, but, the keys don't, I'd say that it's probably a software issue (especially since it happened after your upgrade to ICS). I mean, why would all the keys stop functioning, but, the trackpad still work? I'm not sure what the internals of the dock are like, but, that just seems strange. If it were one or two keys maybe, but, all of them?
Yea, I mean, if you can find a retailer that will let you put the dock into another tablet, maybe a display (especially if it hasn't been upgraded to ICS yet) that'd be a great test. Or, worst case, you can always factory reset (would this make it so you had to upgrade back to ICS? Not sure). Even if not, a factory reset might be a good last ditch attempt to see if that'll fix it.
Also, when you call back, tell them that it happened right after you upgraded to ICS. They should be able to test on there end if they have any problems with ICS and a dock. If they don't, you might have to reset and hope that that fixes it. If not, you'll have to keep trying to get a new one from them, or, buy yourself a new one. :'(