Here is the homepage of the co-op search.
You can also open these up for collaboration by sending invites to others, and then have a whole group of people that can add target search sites/ blogs to your Search Engine.
This isn't as open as I had hoped, because it appears you have to invite your collaborators first. My theory, instead, is to let anyone add a search target site or blog, and then the admin(s) would either approve or disapprove it. I say this because they've done a very nice job on their custom Google Groups. I started one about open - source software sometime ago (has over 200 members now) and as admin, I can go on and set settings for new users, moderate posts, and even kick somebody off if it becomes obvious that all they joined for was to post job-listing spam. So the Custom Search will need features like this to compete and become a true collaborative environment.
I currently have some 1346 blogs in the search facility (you can add sites in bulk, and it accepts both RSS/ATOM feed urls as well as regular HTML urls to a page or site). You cannot add more than a couple hundred at a time, however, since the JSON dies on the vine with too much baggage. Being able to add straight OPML would be a nice feature.
It's funny that I ran across this today, since I had already started on something similar. Now I'm encouraged to continue working on it. (Mine will be better!)
Working with CSS and positioning is a weak point for a lot of ASP.NET developers, myself included. It's a full-time career to become a professional web designer (and from the looks of many ASP.NET sites, that's a self-fulfilling prophecy) -- codemonkeys simply do not have the time or inclination, except in special cases, to earn those kinds of skills.
CSS support in IE 7.0 has been enhanced quite a bit, with over 200 fixes in the release version of the product. I've always used Dreamweaver to do my positioning and styling, not only because it is good - especially 8.0 which hardly ever crashes - but also because it doesn't mangle server tags from an ASP.NET page. So, I can do my layout and CSS, and then save and reload the page in VisualStudio.NET for server-side coding.
But now there is Expression Web. My first impression? Pretty damn slick. It has CSS features, a "web site" facility that's better than Dreamweaver, and you can actually design and live-preview an ASP.NET page - including Master Pages -- with all the ASP.NET controls right in the Expression designer.
Take a look - it's still Beta, but if they keep working on it like this, its a sure winner.