The new Internet Explorer, based on IE6 technology on the desktop, but also has JavaScript bits from IE8 and a few other goodies, will allow Windows Mobile users to browse the web as their iPhone brethren have been doing since 2007, but with Flash support.
Windows Media Player on Windows Mobile has been rather disappointing for several years. Rumors continue to persist that the Zune UI and marketplace will make it to Windows Mobile, if not in WinMo 6.5, then surely by WinMo 7. The Zune player is a nice device that bests the iPod in a few areas and equals it in others. The UI from the Zune player on a Windows Mobile device would be a welcome addition, including such goodies as WiFi sync to your PC and sharing songs with other WinMo and Zune users.
The marketplace will also put Microsoft on par with the Apple App Store, and surpass it in a few areas. Full refunds within 24 hrs will put many at ease when plunking down their cash for an app. Allowing users to use credit cards or have it billed on their monthly phone bill will also make life easier for users, Because MS is charging developers $99 to put an app in the store (the first $99 gets you 5 apps), it should cut down on the junk apps that are found in Apple's store, allowing users to find quality apps faster. I still think it is a HUGE mistake for Microsoft to limit the marketplace to WinMo 6.5 and late only, leaving existing WinMo 6/6.1 users out in the cold. Hope sprints eternal that that position will be changed by the time the store launches this fall.
Speaking of apps, with widget support in 6.5, there should be a lot of smaller apps available for basic things like stock tickers, location based services, weather and more.
WinMo 6.5 is still in development so there could be other changes. WinMo Standard (non-touchscreen) devices have profiles but not Professional. I've not seen information on whether or not MS has rectified this oversight in 6.5 or not. Apps need to really play well with each other too. I quit listening to music and video on my WinMo phone three years ago after I got a phone call during a song. The ringer blaring through the headphones left my ears ringing themselves for several hours after that. The phone and music player have to play nice with each other, pausing music and drastically lowering the volume before letting that ring through.
Keep in mind that in 2008, more WinMo devices were sold than iPhones, but the iPhone certainly seems to have the limelight right now. WinMo 6.5 may have just enough to begin to reverse that trend.