Well, it looks as though another component maker is jumping into the 10 speed mtb group rumor wars. (Although this rumor appears to be a pretty solid one) You have read my takes on the 10 speed mtb stuff here and on The Bike Lab before. Check out what James Huang from cyclingnews.com speculates on here.
I've been saying for two years or more that a 10 speed mtb group was going to be coming. It is inevitable. Once road gruppos went 10 speed, I figured it would be a matter of time, then when 11 speed road gruppos came out, I knew it was a certainty. Look for a ten speed mtb group from SRAM or FSA next spring. Shimano won't be far behind. The next XTR will most assuredly be 10 speed.
What does this all mean for the "average" mountain biker? Most of this 10 speed off road gear madness will be directed at racers. It will be heinously expensive. And......it won't be durable enough for everyday use! So, will 10 speed trickle down to lower groups? Will 9 speed someday be on Tourney equipped "mart-bikes"? Will my stuff be outdated in 2011?
The answers are not clear, but my feelings are as follows: Yes, yes, and no. Let me explain. First of all, there is no doubt that eventually 10 speed mtb stuff will be on XT equipped rigs and probably down to what we know as LX now. (But will be re-named most likely) SLX stuff will stay 9 speed, and parts makers will offer 9 speed as All Mountain/Free ride/ Down Hill stuff in the future. It will be a no brainer to go this route since they will still be catering to the racing crowd and not lose the "core" mtb'ers in the process. (Not to mention the fact that any AM/FR/DH'er worth his salt would destroy a 10 speed mtb group in one ride.)
I would change my opinion only if one thing happens with SRAM's new XX group and that is if they go to 140OD on axles. (Really, the smart move is to go to 150mm, but I think they would split the difference there) Why would this make a difference? Because instead of making everything thinner to stuff one more cog in there, as they have been doing for the last 20 years, the cog thicknesses could remain the same, and durability would not be affected. This obviously would be a revolutionary move that would make all your bikes obsolete in one fell swoop. Not a move to be taken lightly, so I wouldn't expect that to happen.
Nine speed "mart-bikes"? Yep! Look for ten speed mtb hardware to push 9 speed down spec to entry level parts. "Big Box" retailers would love this, because in consumers eyes they would be getting a "bike shop" level drive train at "mart-bike" prices. Not only that, but the inevitable increases in goods could be offset somewhat by adding this "benefit" to department store bicycles. I think it is a done deal once 10 speed hits the upper levels.
Will your stuff be outdated in 2011? I don't see that happening. But what will happen is that seven speed stuff will be gone, (It almost is now) and 8 speed stuff will be phased out over a period of time. So, if you are into upper level 8 speed, you'd better start hording now. The jig is up for your preferred parts. Nine speed stuff should be produced for the foreseeable future. I don't see that going away anytime soon.
Finally, I think ten speed mountain bike gear is ridiculous and will be problematic unless we go to a wider rear hub spacing. (James Huang hints at this, I think, when he reports on the nature of the cassette for the upcoming XX SRAM gruppo by saying, "......but modified for better performance in muddy conditions with a more open architecture." I mean, there isn't much "opening" one can do on a current 10 speed cassette. Especially in terms of fouling with mud or plant debris. (Did I mention that 10 speed stuff will be problematic?) A widening of the spacing is what would be effective, and widening the over lock dimension of axles would accommodate this. Either that or dish the wheels some more. (Gah! The thought of that makes me shudder! )
Well, all this will certainly pale in comparison once FSA launches their rumored 11 speed mtb stuff!