In my view, the risk of super-agile development is that key bugs can get overlooked, which is why prioritization is so important.

This Code Yellow incident might just be an isolated case or it could potentially be indicative of some larger code quality concerns within Google. In any event the fact that it was recognized and is being dealt with is a good thing.

Overall though, Google Chrome itself is getting slower, for other reasons.

Extensions for Chrome actually slow down Chrome's performance. It's something that Google developers recognize and are now working on. Extensions are currently in the dev-channel build of Chrome and not yet fit for broad consumption, but the plan is to move them into the beta builds soon.

Google has pitched Chrome on the merits of its speed since day one. It'll be interesting to see as time goes on how many trade-offs (if any) need to be made to continue to make both the browser and browser releases themselves faster than before.