105 has always been good enough for serious enthusiast use. For the past 10 years, Tiagra and Sora have also been good enough for serious use. The biggest thing this changes is that people won't be able to debate whether 105 or Ultegra is the sweet spot in the Shimano lineup any more. Frankly, I think this is a logical result of their trickle down technology strategy. There's only so much improvement that can be made to mechanical shifting, and as you move to more and more cogs there's a serious danger of that curve starting to go the other way.
I'd really like to see a company emerge that manufacturers 10-speed Campy ergo clone components. The patents have expired, right? I'm not sure what prevents this other than me being the only person that wants it. It probably won't be long before I'll be able to 3D print all the pieces and make my own for a reasonable cost. Can you 3D print replacement hoods yet?