I do indeed have sympathy for the fact that you can't use your Indigo
IO anymore. I'm also looking a new laptop, and it seems that there are
very few, if any, laptops that still have Carbus slots. Most seem to
have some flavour of ExpressCard.

I just got myself an Lenovo R61. the fundamental reason was due to the lack of cardbus laptops out there, they are about but this issue greatly reduced the pool to choose from. i'm very happy with the r61, i use the rme multiface so i don't know much about the intel card but initially i found it hard to get good performance from it.

also, there is a large amount of resourses out there for thinkpad laptops and linux. this helps in the short and long term.

if you are coming from mac, pre-installed ubuntu is definately a bonus.

good luck to anyone trying to choose a laptop. its a terribly hard decision and world of comprimises.