They will be - at least early press releases depict the X0 and X9 groupsets as 2 * 10, using XX-esque cranks and cassettes.
Regarding your earlier outburst, your subsequent posts reinforce my point. My concern is not for the racer, wannabe racer or hardcore e-biker, thus not anyone reading this thread. My concern is for the consumer, the punter. X7 and SLX are priced very accessibly and found on bikes down to $1000, almost a throwaway price these days. I believe that longevity and low maintenance requirements of gear at this price level have more to do with positivity of experience than performance or gear range does.
As for your personal attack on my experience - I work on around 2000 bikes per year, ranging from shitters, to mid range, to high end road and mtb. I'm in a good position to correlate bike type with user-maintenance, miles done, and subsequent wear. I also work on the retail end, selling bikes, parts and talking to riders about their experiences with their bikes. I've been racing and riding all sorts of bikes for over 10 years. It's foolish to attack people you don't know, no matter the forum. My Jack Russell will never learn that, but you might.
My experience tells me that 9spd drivetrains (chains, cassettes, chainrings) wear out slightly faster than 8spd drivetrains, but that 10spd drivetrains wear out significantly faster than 9spd drivetrains. I'm not an engineer, but have theorised that this is due to the narrower load-bearing surface in the 10spd chain coming in below a deformation threshold with typical rider power inputs, maybe an engineering student here can help with that one.
Chain wear aside, there are also issues of shifting accuracy as has been mentioned in this thread already. The more sprockets you have to squeeze into a 130 or 135mm dropout, the closer they are, and as such the smaller the detents in the shifter ratchet. This requires that a smaller unit of cable pull is utilised in order to make the derailleur pull across the smaller distance to the next sprocket. With 100% efficient cable this is not an issue, but no shifting cable transmits force with 100% efficiency. There is always some compression of the outer cable, some stretch of the inner cable which reduces this efficiency.
With new cable and perfect adjustment, 10spd systems shift fine. In reality though, it's a bicycle. It gets ridden outside, dropped, leaned against things, left in the elements and generally neglected. The efficiency of that cable is only going to get worse the minute it leaves the shop or workshop. Let it get below a certain level and shifting goes to rubbish - and that level is higher for 10 spd systems than 9, for 9 than 8.
That's just cable, when you include issues such as jockey wheel and bushing wear, misaligned hangers and derailleurs, worn cassette teeth etc, it gets much more complicated.
See you at the races.
- Joel