As we're currently mulling a full transition to VS2008 and .NET 3.5, I've been investigating VSTO3 and ClickOnce once again.  My initial encounters with VSTO and ClickOnce were lacking.  With regards to VSTO, I didn't find anything that I could do with it that I couldn't do without it.  Indeed, it's more of an extension of the extensibility model which provides some under the cover plumbing than anything else.

The decision to attach ourselves to VSTO3 and ClickOnce is no light matter.  Luckily, Cindy Meister (Office MVP) and Mary Lee (Microsoft) were kind enough to weigh in on the matter over at the MSDN forums.

I think all Office developers should head over and take a look as it contains a wealth of information (and clarifies some common misunderstandings) with regards to VSTO and ClickOnce.

Microsoft has a very powerful set of group policy administrative templates which allow administrators to set configuration options for Office globally for all users in the domain.  This makes many development scenarios much easier since it allows you to easily ensure consistency in terms of Office configuration instead of writing custom code to do it in your add-in.

You can download the templates from MSDN.

You can find more details about installing and using the templates here.

And in case you were curious, here's a screen cap:

This is a must explore set of tools when working with Office applications.