Where the hell did Bing come in? Some people use Google Search and Hotmail. You're not locked into a company. Furthermore, this was never about search, this was about more complex applications. If Google Search told you to download Chrome or else you couldn't use it, you can fucking bet users would start using Yahoo. Laziness trumps everything else. That's why I use Mibbit rather than downloading an IRC client.
Hotmail leads Gmail by 13 million uniques. Gmail is the fourth-largest service. Just because it's the best doesn't mean it's the most popular.
Real enough for you?
>> That's why I use Mibbit rather than downloading an IRC client.
You have good taste ;) FYI, On Mibbit, IE usage is at 26%, and falling.
In webapps, IE is a very small minority, and falling fast.
A lot of people using IE right now are either forced to use it for corporate purposes - my mother has to use it on her laptop - or they're completely illiterate. If something messes up, they'll see it as Gmail breaking.
The solution is graceful degradation, but that won't force people to switch.