I know the product is rather new, but they do make a solution. When we did our RFI, we invited 3COM to particiapte. Our goal was a gateway solution connecting to 80 Nortel Option 11's, with the intent of replacing the PBX's in the future. There were several other vendors also invited, and 3COM was the only vendor to come in, meet with us, hear what we wanted to do, and say no thanks.
According to the local 3COM rep, they could not do a Q.SIG connection to the Nortel PBX at all. Everyone else who makes PBX's, that I know of, can do this. Possible red flag, who knows.
I would seriously look at other options, not just 3COM.
Hope this helps,
Scott M.