A few people have already mentioned .NET 1.1 SP1 (in addition to .NET 1.0 SP3) being available as of 8/30/2004... but since I've been a little busy, I didn't notice the availability until I updated all of my systems last week. A couple of people of mentioned that SP1 has affected their ASP.NET applications while others have mentioned problems with the installation process hanging. My experience has been extremely smooth with installing the service pack via Windows Update.
Now, for the problems. The only problem that I've run into so far hasn't been with the .NET 1.1 SP1 update, but rather the Windows XP SP2 update. I'm using Dart's Secure FTP .NET component and after applying all the available updates, the .Close() method now just hangs indefinitely. I spoke with the guys at Dart and they've found that there's apparently some timing issues with interacting with the firewall mechanism in XP SP2. They've already fixed the problem, it's currently in beta and they'll be passing it along to me hopefully by the end of the day so I can test accordingly.
However, when talking with them... things are very different on the ActiveX front. Many of their customers for whatever reason are continuing to use the ActiveX versions of their components. Apparently, .NET 1.1 SP1 (and .NET 1.0 SP3) has changed the COM Interop mechanism and when importing a COM object, the wrapper (or something) being created is not working as expected causing the imported component to not work. They've got an open ticket with Microsoft on this issue and have told me that this issue is not isolated to their ActiveX components, but with the components provided my many other vendors as well.
So, if your using any third-party ActiveX components... upgrade with caution and test accordingly before mass deployment. I haven't experienced this problem first hand (as yet), but figured I'd pass the information along.
Someone also mentioned that .NET 1.1 SP1 should have been .NET 1.1.1 and run side by side. I haven't actually tested my Web Services problem to see if it's fixed, but I'm not sure that I agree with the idea. There are several problems within the 1.1 framework that need to be addressed and with the fact that there are so many changes being done with Windows XP Service Pack 2; the framework must be updated to handle these changes. My applications that are deployed on Windows XP should continue to work as expected with the 1.1 framework... no matter how Windows XP SP2 changes things. This requires that the framework be patched. Now, I do agree that service packs in general should not change behavior... change in behavior should be a new version and run side by side. So there is a somewhat well defined line with what should be in a service pack and what should be relegated to a new version release, however, given there is only so much time, money and resources; it makes some sense as to why all of this would be crammed into a single release. Do I agree with it? No. However, I do understand.
Here's where you can directly download the various service packs:
Of course, I recommend using Windows Update.