@Allan Rutland 15:55 "But..."
I assume by Server 2003 SBE you actually mean SBS?
And how does the WHS PP2 turn WHS into SBS?? It definitely doesn't in many many areas.
http://www.microsoft.com/windows/products/winfamily/windowshomeserver/pp.mspx
Even without PP2 installed you can still use IIS for other sites, install FTP and a few other apps through the Add/Remove wizard, etc. But the OS license and user accounts are still limited compared to SBS, as is a lot of other missing SBS features (Exchange, Sharepoint, OLSB, WSUS, SQL, RWW, SMTP/POP3, etc. etc. etc.).
I'm running WHS on one of my systems at my house, and it is really nice. Of course I have most of the "WHS family" stuff turned off, and I'm using it more like Server 2003, and headless via remote desktop (NOT remote access). IMHO WHS's biggest downfall is the crappy drive extender system, I just keep all of my additional drives outside of the pool.