Hmm, maybe I'll look into T-Mobile and Lumia then.
One of the things backing up my decision is whatever laptop or PC I decide to get. I bought a Macbook Air a couple weeks ago, long story short, it and its replacement were both defective, and I just opted to get my money back. Now I'm trying to decide if I should go with another Air (this time from the Apple store instead of Best Buy), a PC Windows laptop, or a desktop. So whatever I pick, I think will have a big factor on what phone I get, as I'll be tied into one of those ecosystems.
Having a Mac doesn't make you locked into getting an iPhone, just like getting a Windows PC doesn't get you locked into getting a Windows Phone.
Sure it's easier to have everything from the same company, but a) diversity is awesome b) don't keep all your eggs in the same basket.
If I were to graduate now (as a student I globe-trot way too much to invest in any serious hardware) and buy a desktop/laptop/tablet/phone, I'd get a Windows desktop with Ubuntu on the side, a MacBook Air, don't know yet what I'd get on the tablet front (Surface, Surface Pro, or iPad), and a Lumia 920. I was seriously anticipating the iPhone 5 but the conference left me severely underwhelmed.
There's no Android anywhere in that list but, as much as I understand the appeal the OS has to some, it just isn't my thing. My brother is an Android guy and I've used his S II and Nexus 7 quite a bit, and I'm even currently rocking a Galaxy Nexus because my Omnia 7 doesn't work on US 3G, but it's not what I want on mobile devices. I love tinkering on my computer (I'm a software engineer after all), but I don't want to deal with roms and flashing and all of that on a tablet or a phone. And even if stock Jellybean is much better than Donut or whatever it was that the Hero I used before getting the Omnia had, it's still, IMO, subpar to Windows Phone in terms of UI.
I've felt like iOS's UI has gotten staler and staler over the years, I was really hoping for something new with the iPhone 5. It'll probably push me away from the iPad and towards the Surface on the tablet front.
Of course, no interest in Blackberry or a Kindle Fire (lol)