gocyclones,
MobileSSH has the advantage of not requiring a server; however, that's not your only choice -- there's a way to do MobileSSH via a server:
If you need a form of authentication through your BES, you may wish to try Idokorro MobileAdmin. You can have two layers of encryption with it (SSL/TLS encryption through the existing BES/MDS encrypted tunnel). MobileAdmin supports RSA SecureID.
On top of the Windows/Novell/BES/etc administration features, it also includes Mobile Terminal (a clone of MobileSSH) that requires the MobileAdmin server to work. This can allow you to monitor all the connections coming from the BlackBerries on the field, through full logging, if you need full auditing of all your telnet/SSH connections even to non-Intranet hosts, etc.
MobileAdmin's "Mobile Terminal" feature does not yet have the MobileSSH 2.0 codebase yet, however MobileAdmin's own "Mobile Terminal" feature should eventually have all the features from MobileSSH 2.0 (such as color and 5250). Essentially, MobileAdmin is kind of a massively expanded superset of MobileSSH since MobileAdmin already includes Mobile Terminal.
All software MobileAdmin, Mobile Terminal, and MobileSSH can be installed simultaneously on a BlackBerry (this also gives the advantage of multitasking two telnet/SSH sessions simultaneously too, by running MobileSSH and Mobile Terminal simultaneously!). I am sure that if you are a fully paid MobileAdmin customer, Idokorro would be happy to include a registration of MobileSSH 2.0 if you need the extra features of the MobileSSH 2.0 at least until Mobile Terminal has all the features of MobileSSH 2.0.
Hope this helps. Anyway, please note, I am going from my memory and am posting on my own behalf, not on Idokorro's behalf -- To confirm, you may wish to go through official channels via
contacting Idokorro.