You would not believe what some of my co-workers have achieved in Excel and VBA. Complete scheduling systems that tie in to three databases, complicated code that analyzes metal removal. And they don't consider themselves programmers.

The lack of programming knowledge mixed with VBA makes for an maintainability nightmare, but hell, they're doing a good job of Getting Things Done. I would love for Microsoft to replace VBA with a language that these people can still use, but is easier for a programmer to take over once the scope increases past the abilities of Excel. I'm not sure if javascript is that language (I think a C# derivative would be better), but it might be.

There are lots of business uses to being able to automate documents. Being able to do so in JS rather than VBA would be a bonus for companies that have a need to do so, but don't want to train people in a language that's not used anywhere else.

It might also allow MS to do nifty online things.

I'm looking forward to this. I've needed to embed a web app into outlook, and writing an outlook add-on to do that was an exercise in frustration. Not sure how much javascript can solve that, but I doubt it will make things worse.

What else should they be doing besides improving the product?

Office has millions of users. On one of the Office developers blogs, there was a mention of the accusations of "bloat". His response was something like "Do people think we just add code to Office for the sake of adding code? Features are added in response to customer demands."

Sure, not every release will have compelling additions for every user, and it's possible your goals are filled by an earlier version. The last two versions (2007 and 2010) have made it vastly more usable.

Because it's a sharepoint platform!