In anticipation of the GPL release of Doom 3 code, hopefully soon, I sent a note to John Carmack asking if the Creative Labs patent would still be an issue:
I believe you've said publicly that you are planning a GPL release of the Doom 3 source code, but I remember around the time the game was launched you had Creative holding a patent on the shadows algorithm, and you assuaged them by including support for EAX. Is that still causing problems?
When we release the code (no date set), anyone that uses it would potentially be infringing. There are workarounds at a modest performance cost.
I think this means that id would have to use GPLv2 rather than v3, but I haven't really read deeply about the new patent clauses in GPLv3.