(10/4: note, I've been adjusting this post as I have gleaned or have been given, a little more information so that it's as helpful as possible)
You are not alone. There is so much coming at us at once and it has started to become a blur.
I needed to get my brain organized again and thought I would share what I learned.
.NET 3.0 was a wierd marketing move because it sure as heck sounds like it's a whole new version of .NET, but it's really not.
First a pretty picture:
The Framework
.NET 3.0 is.NET 2.0 plus the four new components. Those four core technologies are called the “.NET 3.0 Components“.
When you install .NET 3.0, it will put the .NET 2.0 framework and the .NET 3.0 components on your computer. If you already have .NET 2.0, then it will just add the 3.0 components. If you have Vista, it's all there already since those .NET 3.0 tools are a core part of Vista as well. Looking in your folders, you will see the .NET 2.0 stuff where you are used to seeing it - in Microsoft.NET\Framework\V2.0.50727. There will also be a Microsoft.NET\Framework\V3.0 folder that has just the four .NET 3.0 components in it.
Nothing in For the most part.NET 2.0 is not really changing. According to Scott Nonnenberg's comments (thanks Scott!), there will be Service Pack level fixes to .Net 2.0 components to avoid breaking changes. That's almost “nothing“, but it's still something.
And (again from Scott's comment) no more hints about .NET 3.5 naming - that's it: “officially named .NET 3.5“, as it adds the newer pieces (e.g. LINQ) into the Framework.
.NET 3.0 and Vista
The .NET 3.0 components are part of Vista. So programming with these components also allows you to leverage what is new and shiny about Vista.
Visual Studio “Orcas“
Like the relationship between .NET 2.0 and .NET 3.0, so goes the relationship between Visual Studio 2005 and “Orcas“. Orcas adds stuff on to what is already in VS2005: development tools that let you work with the .NET 3.0 stuff. For example, UI tools for building XAML (“Cider“), project templates and intellisense for the components, a UI tool for WCF as well. The last is not in the current CTP, by the way. So everything you already can do with VS2005, plus more.
ATLAS
First of all, ATLAS isn't ATLAS any more it's “ASP.NET AJAX“. AJAX is an extension to ASP.NET 2.0 that provides client side scripting libraries. It also has ton of controls that come with it. ATLAS, err, ASP.NET Ajax is not part of any of these other releases. It is currently autonomous and it works right along with VS2005 (though it's still a CTP). Hopefully it will RTM by the end of the year. That will be v1.0. Then it will be wrapped into Orcas and get more goodies as well.
LINQ/C#3/VB9
These will be part of Visual Studio “Orcas“.
ADO.NET vNext
It's very tempting to call this ADO.NET 3.0, but that makes it sound too integrated with .NET 3.0 which it is wholly unrelated to. ADO.NET vNext will be fully integrated with LINQ as well as adding some other awesome data access capabilities. But it is not coming out any time soon that I know of. (10/4 - I've noticed a few other non-MS bloggers mention this coming out with Orcas and will update this post when I get some concrete info) Update: A little more digging comes up with at least this blog post from the WinFS team blog of June 26... a reference to “ADO.NET for Orcas“ and Alex barnett's June 21st post that also talks about “ADO.NET innovations planned for the next verion of Visual Studio (Orcas).“ and then goes right into Entities. So that's good enough for me:
So, my revision is: ADO.NET vNext is planned for the Visual Studio Orcas release as part of what is being referred to, as per Brad Abram's “hunch“ as .NET Framework 3.5. (heh, now I know it's officially .NET 3.5!)
Am I making all of this up?
No. In addition to what I thought I already knew, I have spent a lot of time reading through “futures” documentaiton on the C# , VB9 and LINQ sites, on the ADO.NET site, on the Visual Studio site, on the .NET Framework site, the ASP.NET AJAX site, in forums and in blogs written by Microsofties.
So in summary....
Wave 1: .NET 3.0 comes out soon and just adds on some big features to what we already have to work with.
Wave 2: .NET 3.5 is released along with Visual Studio “Orcas” bringing us the new language versions as well as LINQ, tooling for the .NET 3.0 stuff and an embedded and shinier version of ATLAS v1 and ADO.NET vNext. I've heard this referred to in passing as .NET 3.5
Wave 3: ADO.NET vNext comes out someday...I'd say “and not a day to soon“ except I still need time to gear up for it! (10/4 - as per above note ... with Orcas? I'll update this post when I know for sure.)