Well, you dont have to 'catch up', if your old tools works for you, just use it ! you dont have to learn the details of of a new tool just because its released, unless you feel 'in the mood' and the inner 'geek guy' gets bored and takes learning as a pleasure. when a new tool emerges, its good learn a bit about its general charastertics and important changes, but nothing is forcing you the jump over.
For me, the need of VS upgrading is driven by the new feature in the .NET Framework, and VS itself works pretty much the same, and the reason against a lightweight texteditor is primarilythe integrated debugger. yes, to me, 'IDE' is pretty much that, 'Intergrated DEbugger'.
That said, I do hop VS can be more modularized, and those mountains of features can be selectively installed / loaded, I remember its actually a considered goal in the early days of planning for Dev10, but obviously the transition to WPF, the hardworks for WP7 and much more heavy tasks have put this feature aside, I hope it will rise again for Dev11.