Unbranded Flagship Windows Phone

We all know that Microsoft is gearing up to offically announce Windows Phone 8 soon. I'd love to see an amazing flaship phone with a great screen, camera, battery life, etc. However, one thing that I'd also like to see is an unbranded option (aka unlocked and not tied to any specific carrier).

Google does this with their Nexus phones. With the current Galaxy Nexus, you can either buy a "branded" version from your carrier, or an unbranded version directly from Google. Sure it costs more, but the end user also gains a whole lot of freedom.

With Windows Phone 7, the closest thing was with the Lumia 800. However, Microsoft tied it down with a bunch of other accessories. In addition, there were a couple variants with different compatible frequencies. Depending on which model you had, you may or may not get great 3G service.

What I'd like to see is a flagship phone that is truly free. It should be sold as just a handset, and not tied to any specific carrier. Allow it to support every major 3G frequency as well (I don't want to see any optimized for AT&T nonsense). Obviously it would only support GSM carriers, but that shouldn't be a big deal since there are plently of those. Sell this directly from the Microsoft Store to keep things neutral as well.

I feel that this would really help things for Windows Phone 8. Those who want the freedom to pop in any SIM card and have their phone work would love this. Nothing is stopping them from also selling it subsizied with specific carriers as well. This would keep them (somewhat) happy as well.