BlackBerrys may be the most established smartphones in the corporate world, but Global Crossing is one corporation that can't wait to get rid of them.The telecommunications firm, which provides networking services such as VPN, video conferencing and VoIP in 60 countries, is on the hunt to improve unified communications for its 5,000 worldwide employees.With this goal in mind, Global Crossing is taking the leap to Exchange 2010 from Exchange 2007 for its e-mail archiving capabilities, connection to cheaper storage, and as a replacement for its current voicemail system.But the Exchange 2010 migration is also a chance for Global Crossing to wean itself off BlackBerry smartphones and onto Windows Mobile 6.5 phones, thereby eliminating the fees required to make BlackBerrys available to employees.Slideshow: Windows 7 in Pictures: The Coolest New Hardware"RIM requires that you pay for a license for the BlackBerry servers," says Steven Schafer, Director of Network Services at Global Crossing. "You pay a license for every BlackBerry user that you have connected, and then you also pay for support and maintenance for the servers and users."But Is WinMo 6.5 Good Enough?Despite the cost savings Global Crossing could reap by ditching BlackBerry servers and licenses, Windows Mobile 6.5 has faced some harsh criticism since it launched a month ago. It was mostly panned by critics and, based on recent customer satisfaction studies, it has fallen way behind the iPhone and BlackBerry in the smartphone race.[ For complete coverage on Microsoft's new Windows 7 operating system -- including hands-on reviews, video tutorials and advice on enterprise rollouts -- see CIO.com's Windows 7 Bible. ]Most of the gripes about Windows Mobile 6.5 are that it is a stopgap before the arrival of Windows Mobile 7, with underwhelming interface and touchscreen features. But even though WinMo 6.5 is not being hailed as a great mobile OS for consumers, critics admit that it's a solid enterprise mobile OS given how well it integrates with Exchange.Schafer is counting on such a smooth integration with Exchange 2010 and Office Communications Server. It's what sets WinMo 6.5 apart, despite its lackluster reviews, he says, adding that he expects more enhancements with the arrival of Windows Mobile 7 in the second half of next year.Also, unlike any other mobile devices, Schafer says, WinMo 6.5 phones are the only ones that have the Outlook Mobile client that uses the new features in Outlook 2010 such as Conversation View of e-mails and having audio and transcriptions of voicemails delivered to inboxes.Opening Up ActiveSync in Exchange 2010Getting everyone on Windows Mobile 6.5 phones won't be easy, Schafer says, given that only 20 percent of Global Crossing users have corporate-owned phones and 80 percent buy their own phones. Global Crossing will still have to support that 80 percent.But that burden will be eased with improvements in Exchange 2010 to ActiveSync, Microsoft's mobile protocol for synchronizing e-mail, contacts, calendars and tasks. Microsoft has opened up ActiveSync support to a wider array of mobile devices. Companies such as Apple, Nokia and Palm have all licensed ActiveSync so their mobile phones can connect to Exchange.It's worth noting that the iPhone and Palm Pre do not have all the Outlook e-mail features that a Windows Mobile 6.5 phone has because Apple and Palm have not adopted everything that's in the ActiveSync standard. But, Schafer says, as time goes on, he believes Apple, for example, will start to add more ActiveSync capabilities to the iPhone.The BlackBerry\/ActiveSync DisconnectThe main problem with BlackBerry, says Schafer, is that it's a non-ActiveSync device. As a result, you have BlackBerry servers running alongside the Exchange server, and also every mailbox with a BlackBerry connection to Exchange uses five times the connection resources that a mailbox with an Exchange ActiveSync client uses, says Schafer."I'd prefer all our users be on a Windows Mobile device because it integrates the best with Exchange," Schafer says. "But at the same time I would much rather have an employee go out get an iPhone than a BlackBerry because an iPhone uses ActiveSync and therefore costs us nothing, and a BlackBerry costs us money."At this point, Shafer says Global Crossing will still provide Exchange support for current BlackBerry users, but it has stopped providing new licenses and plans to reduce the number of BlackBerrys by attrition. New hires at Global Crossing who need a corporate-owned phone will not be getting a BlackBerry; they will be getting a Windows Mobile 6.5 phone. If they want to use their personal BlackBerry as their work phone, they will be out of luck too. "We're not kicking people off BlackBerrys but we're no longer allowing new hires to be on the BlackBerry platform," says Schafer. "And we're finding more and more that people want to be on ActiveSync phones."Shane O'Neill is a senior writer at CIO.com. Follow him on Twitter at twitter.com\/smoneill. Follow everything from CIO.com on Twitter at twitter.com\/CIOonline.