It's good that they will keep working on IE, but since they will only release these "previews" for a year, that means new features will always be way earlier in Chrome and Firefox (soon) with their fast release cycles. IE10 will launch with features that Chrome and Firefox will have 10 months before.
I really hope that Microsoft starts to shorten their release cycles. Releasing once every few years made sense in the 1980s and 1990s. Not so much today.
That is a fast release cycle for Microsoft! It's a step in the right direction. Microsoft is a giant cruise ship trying to compete with speed boats. It won't happen over night, but hopefully it either does happen or they give up. I still feel this is great news overall, it shows Microsoft is aware of the situation. If they ever do truly remedy this (and by remedy I mean a very fast IE release cycle, ideally with automatic updates like Chrome does) it will take them a while to get there. I'm just glad they appear to be slowly turning this cruise ship around.