Sorry to dig up such an old thread, but some forums I've been on, the mods get their noses out of joint if you don't pore over the past five years of posts before you ask a question, reviving an old thread seemed a better option than making a new one.
Anyway, onto the point. I'm going to receive my Asus Transformer soon (one would hope...), and I'm looking for a really well-made WLM client for it. File transfer isn't a huge priority, people have email for that, but I want all the nice, superficial stuff. Having font settings behave the same way on the tablet to what they would on a PC, for instance. Voice and video is kind of the holy grail of WLM clients, but again, not a big concern. Mostly, I want one that has a really clean interface, doesn't look like a stretched out phone app, and actually looks like a WLM client. Not just some IM client that uses the MSNP.
Of course, having it multitask well is probably the highest priority feature, but if I were to settle for just that, I'd use Mercury.