I just moved from Visual Studio 2008 to Visual Studio 2010 (final) and noticed one major flaw:
When I try to use AutoComplete in a C++ source file for managed C++, a small note in the footer appears:
IntelliSense for C++/CLI is not available
Uh, has IntelliSense for C++/CLI been dropped from Visual Studio 2010? Is there any way to get this back? It is rather useful...
You are correct. Unfortunately it has been dropped. You can check this opened issue on Microsoft's Connect website.
I'll just quote them for the sake of the answer:
Unfortunately in this release we had to cut the intellisense support for C++/CLI due to time constraints. If you want to get some intellisense like quick info and memberlist on the native classes you can get it by choosing no /clr support in the project properties.
About getting back intellisense, your best chances for now are using third-party tools like VA Assist for example. I've tried it with Visual Studio 2008 and its IntelliSense is a whole lot better than the default one.
It is available again in Visual Studio 2012.