Based on unique visitors from the US IBP (internet browsing population), Gmail doesn’t even hold a candle to Hotmail (94% larger than Gmail) and Yahoo Mail (190% larger). Gmail’s buzz is obviously much larger than it’s bite.
But you can still go back to the old layout if you prefer.
Overall, this looks like a decent UI update for people that use multiple Google services.
Spam runs rampant on Gmail, but you have options.