Looking at DistroWatch , I see that there are about 100 distros selling some flavor of Linux, including one of my personal small-market favorites, MandrakeLinux. Only a couple of dozen of distributions are packaged by commercial vendors, so that narrows the field.
The field is going to narrow a bit more. Linspire CEO Michael Robertson recently predicted that the number of commercial desktop Linux distribution vendors would decrease during the next year. Some will merge or be acquired. Others will be overwhelmed by the task of marketing a distribution commercially.
The coming shakeout will be a positive thing, Robertson said, because larger, stronger desktop distro vendors will be better able to compete with Microsoft than many small vendors.
Even so, there probably is going to be a shakeout, and that does complicate the distribution selection process. I'm not sure how anyone can really speculate which distros will go away and/or consolidate, as Linux distro companies certainly march to their own drummer, but I'll take a stab at a prediction.
There is no question that Novell's SUSE Linux and Red Hat are the top two players in the distro game, and should be for quite some time. Because Red Hat has historically been more focused on their desktop distribution than SuSE has been, I would say that Red Hat has the stronger offering. Novell is coming on strong after its acquisition of Ximian. But I think Red Hat's longer history as a desktop distro developer gives it the best chance of winning the desktop from Microsoft.
The tables are turned in the server distribution area. I think that Novell's SuSE Enterprise Servero has the best chance of winning the server space from Microsoft. Novell has a larger installed base of network users than Red Hat ever did, thanks to Novell's Netware legacy.
Novell's vendor partnership effort seems stronger to me than Red Hat's. For example, SuSE is optimized for the p5 series servers, though Red Hat is not. One reason for that has been that the 2.6 kernel was not released on Red Hat until RHEL 4 came out in February. Novell beat Red Hat to the punch with a 2.6 version of SuSE.
Right this minute, my prediction is that if Novell keeps up its efforts, then SuSE will win the Linux distro server war. Red Hat's desktop legacy puts it in the lead in the Linux desktop distro battles at this time.
The fly in the ointment of my prediction is that RHEL 4 has so much to offer as a server distribution. In addition to containing the 2.6 kernel, it also will include a rewrite of the Linux's I/O subsystem, which manages transfers of data between systems components. It will also come with a version of logical volume manager, which does disk partitioning. There will also be a huge change to how VMM (virtual memory) handles writes to disk.
RHEL 4 is very likely to be the hot Linux OSS product in 2005. So ask me again in 2006, and I might have a different answer.