eWeek is reporting that Microsoft “is poised to launch this month the next version of its mobile operating system, Windows Mobile 2005, which will incorporate push e-mail capabilities with Microsoft Exchange Server.” This will dramatically alter the purchase decision for companies looking to deploy wirelesses devices.

RIM has always been the favorite because it can push e-mails to the device as soon as they hit the server whereas Pocket PCs and Treos must be set to check for new messages at a certain time interval. Since Pocket PC has far superior supporting software (calendar, contacts, tasks, Pocket Word, Pocket Excel, etc) to RIM, then the ability to push e-mail will make them much more attractive devices.

Now, if someone could just put together a decent keyboard… RIM still has the edge on that feature.