Hi,
Publishing just applications isn't as easy as with Citrix but I've managed to do it, sort of!
However, for each device to connect, you should have a license for, I'm not too sure on what happens with licenses, "I think" that the first time you connect, you get a temporary license that lasts for 90 days, then, after 90 days of repeat connections, the device takes a permanent one. So you need to be aware how many external devices may connect and that may cost you!
Citrix also allows seamless apps, Terminal Services won't be and you could get disconnected sessions depending on what "X" they click, may be an issue.
Citrix also allows Load Balancing, so depending on how many people connect will also place 1 server under increasing load, and what if it crashes and is offline for any amount of time?
Printing is a nightmare, believe me, I support around 1000 external clients and printing needs are unbelievable! You need to disclaimer that if a printer is not supported under Terminal Services, they you won't support it or attempt any curing of it, maybe even give a list of what you will and won't support!
Does this help you any? I'd be interested in knowing what you are going to do, also, where are you based? Being nosey!
Cheers,
Carl.