Here's a good example:

That's breathtaking, especially at 200mm.

But on much shorter lenses, IS is not very important. Even though this thread is about zoom lenses, I must mention that very few prime lenses have IS, and all of the ones that I've seen have been long lenses.

Unless you have an unlimited budget a good tripod can be a less expensive route if you don't need hand held.

I went to a real old fashioned camera store today, Kenmore Camera. They not only had the T2i kit they also had the body only. Way more rare they had a brand new in the box with US warranty Tokina 11-16mm f2.8 at the list price. There is a fleabay dealer (that is Ok) that has the Tokina but they are adding a $100 scalping premium to list.

My lens collection for my 30D is the el cheapo non IS 18-55mm Kit, the only reason I got it was as a $50 Macro, 50mm f1.8 (Mk1 metal bayonet), 17-40mm and 70-200 both f4.0 L. and a canon 1.4x extender. As the 17-40 is my go to lens for stills I added the 11-16 Tokina today and a T2i body. More than I was planning on spending but I'm happy and way less than a HMC40. The 12 minute limit is a non issue for me.

Being a real Camera store I could shoot and try different lenses. The Tokina 11-16 is to me on a par with an L, it's a quality bit of kit. The Canon 10-22 is slower and is the usual inferior non L plastic fantastic fit, finish and feel. The focus and zoom on the 11-16 has very pro feel to it. The Tokina has a legion of good reviews or I would have not bought it as my first non Canon lens for a Canon.

One thing I would like to add is a good set of lenses will be with you as long as your working in the field. A camera will become obsolete after a few years at the least. I'm hesitant to jump into a new body when I can buy the lenses and rent the bodies. At least until a full fledged dedicated video camera with a large sensor comes out at which point I will have attained a nice set of lenses. $800 is not bad for a T2i, much easier to swallow than an 5d/7d.

On the other hand, you can rent an L lens for something like 30/day, while a pro body will cost closer to $150.

That said, if you buy used and keep your gear in good condition, keeping the lens for a few years and selling later in order to upgrade is like a free rental. :)