Not now I wouldn't
1st up I didn't do my homework. I did not ask the BES admin if the latest BB , the Q10 for example, was compatible with our BES server. I purchased said telephone for a colleague , from our telco, only to be a little pissed of with myself for not being able to connect it to our server. One call later and I was informed why, OK I felt like a prat for not doing my homework, such is life...
Due to the fact that we are a megacorp, the BES server will not be getting updated for quite some time.
That means that the latest and greatest BBs are off limits for quite some time to come. I presume that many of the larger companies will be pretty much in the same position. None of BBs new hardware will be compatible with their N-1 generation BES servers, ouch.
Therefore, no , I would not be prepared to invest in RIM Blackberry for quite some time.