Hi,
I have sent an email to TBS support, here is the reply I got on 09 May 2011:
"We're working on the update and when it's ready it will be published on our
website - sorry that it takes more time than probably customers expect to
take, but we're making such updates for all our products at the same time
and recently we released a lot of new products. so, we hope it will be fully
ready within next few weeks."
So I guess we have to wait
Edit: Silly me, I posted the message without checking first; there is a new driver available for 8921, you can get it here: http://www.tbsdtv.com/download/common/linux-tbs-drivers_110523.rar
For all cards, see: http://www.tbsdtv.com/english/Download.html