Dan

I don't know if you call T-Mo whether they will send it to you. usually the carriers choose to release this stuff once they're geared up to support it which can be sometime after the s/w is released by RIM or the device manufacturer.

I'm based in the UK, and using O2 as the carrier. The link to the download for this s/w is O2 Xda

but i have no idea whethe this is the same device as the 'dash' nor whether it will work for you.

Having said that everytime I've played around with connect on Sony Ericcsson I've had to play around with getting the sw from a foreign carrier and it's worked fine.