From the wonderful hub geeks over at Hubstripping.com:

"Shimano announces a 11 gear hub. The range will be 409% (Alfine 8 gear 307%). The hub runs in a oil bath like the Rohloff Speddhub. This should result a higher efficiency and longer lifetime. The price will be 300,- Euro release data is September 2010."
Can't afford a Rohloff? This is as close as you're gonna get.
I've had the Alfine 8 speed since July and I love it. Hopefully the 11 will be another step in the right direction.
Fingers crossed that it will be beefy enough for mountain biking.