<< Does anyone know if the Acoustic Edge supports connecting to the Creative's DTT2500 or DTT3500 via a digital connector? The reviews that I've read (AFAIK) do not mention this. >>
The AE has an RCA format SPDIF. The DTT2500 and 3500 both have RCA for SPDIF input (the 3500 also has Optical, but there's no particular advantage, the AE has RCA and both speakers do so you're set), the DTT2500 and 3500 can also accept an SDPIF signal in through the mini-DIN, this only works with creative sound cards becuase it's proprietary, but if you want AC-3 input, the RCA works fine. The problem is that though the 3500 is touted as a 5.1 speaker set, it only has 4 analog inputs. It can accept 6 discrete channel input through the mini-DIN, but not through analog. Creative put this stupid proprietary connector on there. You can get proper 5.1 if it's encoded in AC-3 format, but games don't use AC-3 format, so you're stuck to 4 for games, if you don't use Creative's mini-DIN
<< Also, are there any breakout boxes for this card, similar to the SB Live! Platinum? >>
No but the AE does have Digital I/O build onto the card.