Just in case you're using VS.NET 2008 Beta 2 with C#...
If you're using C# and VS.NET 2008 and you're typing some code like:
CustomCollection<MyType> items = new CustomCollection<MyType>()
foreach(OtherType other in OtherTypeCollection)
{
items.Add(CreateItemFromOtherType(other));
}
where CustomCollection<MyType> implements IList explicitly (void IList.method(params) {} ),
you will run the risk that the IDE collapses with a crash. This is a known bug and it is fixed before RTM (yay!), but it still can cause headaches for the early-adopters of MS' next IDE. So you have been warned 
. Full report here.