Windows Mobile has many things it could be doing better, and updates are near the top of the list. Currently, you have to get your update from your manufacturer (HTC, LG, etc.), but it looks like Microsoft might be changing that with Windows Mobile 7.
Windows Mobile 7 will change the way you view your phone. We aren't just building a me-too iPhone or RIM competitor; we're changing the way customers use and experience their device. In the OS Platform team we are responsible for the OS, file systems, security, hardware platforms and drivers, networking & connectivity, location framework and updateability. In other words, we build the foundation upon which the rest of Windows Mobile is built, Microsoft Careers
Source:→ Ars Technica