Even with all of these goodies, there are still some big holes to fill. A large one is the lack of support for several Virtual Private Network (VPN) protocols, namely PPTP, L2PT, and IPSEC. This means that if an enterprise has a tough security policy that utilizes one of these protocols, the Windows Phone 7 user will not have access to corporate data or Exchange. This could definitely slow enterprise integration.
Another major hole is the lack of Wi-Fi and USB tethering. If you travel for business tethering is an indispensible lifeline. All of the other major operating systems can do it now, and Windows Phone 7 needs to catch up here.