I've been running SP1 at home and at work for almost a month without any issues. As for the Terminal Services Web Client, I use the MMC snap-in, so I don't know whether SP1 would break it or not at work. The MMC snap-in stills works like a dream and you can have open Terminal Services sessions to multiple machines at the same time! You can find the whole TSAC package
here. TSMMCSETUP.EXE will install the Terminal Services Snap-in as 'Terminal Services Connections' in the 'Administrative Tools' section, which can be found either in the Control Panel or in the Programs menu.