Do you mean that the local printers do not show up. I presume that your TS users are working remoteley??
Or do you mean that you TS users cannot connect to the office printers??
If it is the latter, I don't see what mapping the printer to LPT1 would do so I assume it is the former.
You will find that you have much fun and games connecting local printers via TS, especially local USB printers and even more so the multi function units.
I have gone through this process before, but am skinny on detail.
I seem to recall it involved installing the printer drivers of the remote printer onto the TS machine.
USB drivers don't particularly like installing without the printer being directly connected, so it is *apparently* easiest to physically plug the remote printer into the TS machine, and install the drivers.
Strictly speaking you don't need to do this, but there can be fun and games instaling a print driver for server 2k3 when no such supported driver exists from the manufacturer.
I think you can sort of just install the XP driver, but then you need to ensure that the identification string (or similar) of the driver on the TS machine is exactly the same as the identifaction string on the remote machine. I think there is a (print??).inf file somewhere in the Windows directory structure which you may need to manually update/alter.
Have a look at your event logs, and see what they say regarding 'PRINT'.
Not much of a help sorry, but might give you a few ideas where to start looking for info.
Cheers.