Visual Studio 2005 SP1 recommends /what/?
That's a great way to ruin a message that several of us have been trying to push for several years - the suggestion here is that you should be an administrator because some of the things that you may want to do might require administrative privilege.
That's like suggesting you should turn up for your job in overalls, in case you have to fix the plumbing - when it is not your job to be the janitor.
Yes, some tasks require that you are an administrator. SOME tasks.
Can you develop a .NET program without being an administrator? Yep.
Can you develop a Windows Service without being an administrator? Surprisingly enough, yes. Install and test it - no, but then again, you can test much of the functionality of a service-targeted program without running it as a service. [All of my services run as console-mode programs when I'm testing and debugging them, so that I can more easily interact with them]
I'm certainly not saying that you can do everything without being administrator - but if you're developing a program whose primary usage is by non-administrators, you owe it to them to develop it as much as possible without being an administrator.
That way you won't have to come out with a support document that tells people that they have to make their CFO into a network administrator, or that you have to be an administrator to look at the calendar. If nothing else, it saves you from embarrassment - and with a number of viruses and other malware working from the assumption that you are an administrator, it's so much safer to be non-administrator as developer and as user.
Vista's support of UAC and fast user switching makes it really easy to run as a restricted user, with only the occasional switch of context when you need to do something - or some things - administratively.
[Finally, with a nod to administrators, developers don't actually tend to understand how to properly administer a system, just as administrators don't actually tend to understand what's possible or easy to write an application to do.]
Come on, Microsoft - please let's give the message that running as administrator is the exception, not the rule.