[jibi]

Honestly, if you're look into a solution NOW, and if the Exchange infrastructure is there already, test it out - no harm, no foul. As mentioned, BES does cost extra, in terms of licensing, support, etc., but right now its a MUCH more superior and mature product, from top to bottom. Security concerns surrounding everything about WM5 devices is rarely, if ever, found in BlackBerry devices. There's a positive, sometimes, to having a propietary solution (for the most part). I do think Microsoft has a bright future ahead of them in this market - Exchange 2007 w/ AJAX OWA and better Direct Push technology should be the first step they'll take; the second being about another 1-2 generations of Windows Mobile OSes. Until that point, I'm against their solution (but I'm open to the future of it).