It depends how you set it up. I use and develop for Macs but I’m one of those non-hipsters that prefers working in Windows so I actually write iPhone code in Visual Studio’s editor. Basically I have my code on the Mac in a Samba share, project manage/edit that code via Visual Studio on Windows, and compile/send to device via some scripts I hacked up to ssh into the Mac and execute the makefiles and downloading-to-device. I also have VNC set up so I can remote into the Mac Mini I use for this (even though it is physically on the same desktop as my Windows box) if I need to see UI stuff (useful for using the iPhone emulator in certain debugging situations), but I don’t use that too often. (I could use a KVM instead of VNC for this, but I just prefer to always be in Windows as the ‘host’ OS).
Having said all of that, I’m with you in that I believe they should just stfu and put out a Windows version of the SDK… given the myriad of big problems they’ve got going on with iPhone development though, I think they have bigger things to worry about right now.
I don’t really like XCode (see my post above) and while Interface Builder is OK for Mac apps, good iPhone UIs are so simple (and fixed-size) that I’d rather just built them up manually and not with RAD UI type tools.
Apple could release a command-line only version of the iPhone SDK and that would be more than enough for tons of people who would like to develop for the iPhone on Windows… but I doubt they will.