Can any of the search engines really improve all that much - and have they improved all that much lately? Yeah, Google has Universal Search (but I don't get all excited over that) and Yahoo has improved the appearance of it's pages and search results (but the results aren't all that much better than they ever were). Microsoft has spent the last two years rolling at Live, but for a while, no one could figure out why they called it "Live" and why they bothered at all (and now that Microsofts seeks to buy Yahoo - that's even more true).
However, Ask.com continues to improve in very tangible ways - and even if it doesn't really matter much in the bottom line - because improving Search is not really all that important anymore - people have moved on - I still appreciate all the changes Ask.com has been making - changes you can really see when you use their Search Engine.
I got the news about the latest change from Jay Mettle who mentioned how Compete.com data was being worked into some of Ask.com's search results - the story is on the Ask.com blog.
Also, I wrote in detail about the improvements on Ask.com in a post Ask.com + Compete.com = better Ask Search at The Analytics Guru.