First- IE is the reason I came to work at Microsoft. When I graduated college - I had a number of opportunities in front of me. It was 1998, and startups and consulting companies were all over the place, eager to scoop up every last computer science graduate they could find. All of the opportunitites were interesting - some offered a lot more money than others (no, MSFT didn't offer the most) but at the end of the day, I wanted to work on a product that had a really broad impact, and the IE team had a position that fit the bill. I joined the IE team, towards the end of the "first" browser-war, and shipped IE5, before moving on to MSN.
The second reason that IE is important to me is that I happen to know some of the people on the new IE team really well. Two of the folks in at the helm of IE, Dean and Tony, are former managers of mine. I learned a great deal from each of them. Many of the other folks on the IE team are former collegues from the past couple years of working on Windows, and MSN before that.
IE7 is going to be a great product. I've seen a little bit of what they have booked so far and it's an impressive plan. I can't wait to see it.