Yes, I admit it. I use Gmail for my personal and www.ParadoxalPress.com email (through their Gmail for domain support). Not that I dislike Hotmail, and they have made great strides from the original version of Hotmail.
For me it's a matter of freedom and which software best suits the way I work and the needs I have. And so far, Gmail is the best choice for me... Even if I do work for Microsoft and I would prefer to support our own software. When it comes to my own choices, its a question of what works best for me.
Ok. Enough blabbering, the one thing that does drive me nuts with Gmail is their so-so mobile support.
That being said, I sure wish Gmail had an API (such as some of the other Google services). I would take the time and write a native app to allow WM 5.0 and 6.0 access to GMail accounts. Would make my life so much easier :)
POP Support: Yes, Gmail does have POP support. But it has several problems that i've noticed so far. The first problem is that messages can only be deleted from your inbox if you select the option to have all mail retrieved through POP to be deleted, so deleting individual items through the mail program doesn't work. The second problem is that it does not allow you to take advantage of features such as labels. I've also noticed that some mails are slow to deliver. So although you can "check" your Gmail using POP, you can't really "manage" your mail with it...