First, however, it's important to note how the situation evolved into Creative open-sourcing their binary Sound Blaster X-Fi driver... Back in June of 2006 we shared that Creative was working on an X-Fi Linux driver. Creative hoped to have this driver ready by Q2'07 (even though the first X-Fi sound card shipped in August of 2005). This promised driver would offer full support for ALSA, OpenAL v1.1, and even EAX support.
In the second quarter of 2007, Creative Labs admitted they duped Linux for Windows Vista. Bringing their Creative Sound Blaster series support to Windows Vista required more resources than anticipated, so they in turn devoted less resources to supporting Linux. Their revised ETA put a Creative X-Fi Linux driver out in the third or fourth quarter of 2007, but it would be just a beta driver.
In September of 2007 the Sound Blaster X-Fi driver was finally coming. This driver was in beta form, but it was binary-only and riddled with bugs that put it in more of an alpha state. In fact, the first beta driver didn't even support modern versions of GCC and it only supported Linux x86_64.
A few months later, in February of 2008, open-source support for the Creative X-Fi appeared in 4Front's Open Sound System. This basic Sound Blaster driver came after Creative had supplied some documentation and header files to foster the development of the sbxfi driver, but to most users this is no good considering ALSA is dominantly used by Linux distributions.
In April of last year, Creative tried again at producing a Linux driver, but the driver was still filled with bugs. This time at least it had Linux x86 support and was compatible with GCC 4.x. Needless to say, a year after their Linux beta driver was introduced, it was still in a horrific state.
In early November, they shocked us (and the entire Linux community), by open-sourcing their Sound Blaster X-Fi driver. They put the code out under the GNU GPLv2 that supports the Sound Blaster X-Fi XtremeMusic, XtremeGamer, Fatal1ty, Platinum, Elite Pro, and Titanium series. The source-code was in a workable state, though it lacked S/PDIF pass-through support and compatibility with external I/O modules. Since then, they haven't provided any open-source (or binary) driver updates for Linux.
Nearly six months after Creative open-sourced this driver, there still is no Sound Blaster X-Fi driver in the Advanced Linux Sound Architecture. There was a half-baked X-Fi driver for ALSA that was derived from the Open Sound System X-Fi driver and not Creative's open-source driver, but that driver quickly went into an unmaintained state.
Takashi Iwai, the SuSE developer that originally ported the OSS sbxfi driver to ALSA, has now spoken out about Creative Labs, On the ALSA development mailing list, Takashi states that Creative is not interested in communicating with the open-source developers and they have expressed no interest in seeing their open-source driver included upstream. Takashi continues to wait on Creative Labs to discuss the development of their open-source Sound Blaster X-Fi driver.
ALSA 1.0.20 should be coming about relatively soon, but it looks like it will be another development cycle that goes without any support for these newer Creative sound cards. It appears that Creative has basically shoved this code for Linux out the door and does not want to touch it again.