Terminal Services on SBS in a virtual machine????
Ok I do think someone at Microsoft was not on a good mood some day and decided to write a paper to make the world a harder place for everyone else.
Everyone knows how slow TS is on VMWare GSX (now called something else and free AFAIK) or Virtual Server (free too). The overhead is on the 30-40% ballpark. That is a LOT. So your TS will be slow, unless you are doing all this for one single user. 
Now take that overhead and put all that on SBS 2003 that is already doing everything else like Exchange, SQL, AD, etc and now you will probably have the slowest TS ever in the face of the earth.
If you do not trust me, go ahead and setup this monstruosity.
