Google Apps (a hosted service which manages corporate contacts, calendar, and mail) plugged in to BlackBerry Enterprise Server last spring, but it was targeted to mid-range companies. Well, App Connector has been updated to version 1.5, and with it has come better scaling both for larger and smaller enterprises. For the higher end, Google has bumped up the per-server support to 500 from 250 devices, and for the smaller companies, Google Apps has embraced BlackBerry Professional Software, for rollouts of 30 and under. Just keep in mind that there were rumors awhile back that RIM was going to be ditching BPS, although Unite! was the only thing that ended up getting cancelled.
You can find more info about Google Apps here or their mobile offerings over here.