I love VSTS 2005 and the .NET Framework 2.0, and there's much in TFS that just makes the development process easier than ever. However, we're using the Rational suite of tools for our SDLC because in our SDLC, the VSTS/TFS combination is just not enough. The development cycle doesn't start with the project plan and task level complete and go right into coding - requirements and use case modeling fit in there.
Traceability. This word pops up in almost every vision and design meeting I've been a part of. TFS does a great job with traceability between work items and source code, and enforcement at check-in time is something that just doesn't come out of the box in Clear Case. There's no traceability with requirements because there's no requirements management in TFS, which hurts. Sure, you can extend the process profiles and define a requirement type and use-case model type, but how do you manage them? How do the business analysts (who don't use VSTS) work with them? I've seen demos/prototypes for use-case modeling using the DSL toolkit, which makes a lot of sense - but it's not out of the box and requires the IDE. If Microsoft had an install of the IDE with a requirement management front end, and a use-case designer, I'd have a powerful case for using the entire toolset.
Believe me, I understand the partner strategy that Microsoft has. It's great that there's so much opportunity for VSIP partners to sell great tools that integrate into VSTS, and hopefully, Team Foundation Server. However, I've seen Borland's CaliburRM tool, and there's nothing there that shouts “no brainer” to pick it over RequisitePro. There should be some basic requirements management tools and use-case tools shipped with TFS, with the partner opp to create something much more advanced.
I'm hoping that Microsoft does a few more things to make it easier for those of us who really want VSTS/TFS to get it into our dev houses.
Another thing I'd like to see is more of a provider model in TFS. For instance, if I've got Clear Case as the enterprise SCC, it would be nice if I could just plug it in where TFSC would normally be and have check-in rules apply. I haven't yet thought about the “how” part, but if we're using a 3rd party functional testing tool in place, it would be great if the results of the tests were stored in TFS's data warehouse to take advantage of the great reporting capabilities in TFS. This isn't all a Microsoft issue, of course - Microsoft needs to expose the functionality, and tools vendors need to take advantage of it.
I'm hoping that in TFS V.future, I'll be able to make a tremendously strong argument for making TFS the core of the SDLC, like BizTalk Server could be the core of an SOA or a business process with multiple disparate back-end apps.
Disclaimer: The views herein are my own and are not necessarily the views of Computer Aid, Inc.