Here is an extract from a comment I posted on Bills' blog responding to a question of why google might not be using AJAX for scrolling search results.
... I want to introduce some posibilities as to why google search may not use an AJAX table yet and what value it may or may not add.
First of all, I think that the LiveGrid adds the most value when data is well formed. This type of data is typically interesting to navigate beyond the first couple of pages. A lot of times a user might want to sort or even filter this content based on various fields or characteristics of the content. I think a list of movies fits into this category very well.
As a user of google search, I typically only care about the first page or two of the results. This is because I either find what I am looking for quickly (based on the prioritization) or I give up and try a different search. It seems at first glance that LiveGrid adds only minimal value to this already prioritized type of content.
So should google search stay with paging? Well, as I said above, I still fail in my searches sometimes. It seems to me, that googles prioritization is not always ideal for me. There are times that I just give up because I don't want to navigate through thousands of results.
Clusty uses clusters as an interesting alternative for organizing search results beyond a single prioritization. If I don't immediately see what I am looking for, but one of these clusters captures my intent, I may still have a chance of finding what I am looking for. Now obviously there will be new and better ways of managing and navigating this type of content (perhaps tags will help). However, as it becomes more formed, something like LiveGrid defintely could add more value.
I think that we will see some interesting and fluid navigation mechanisms for traversing such content in the future. Will these new mechanisms look like a table? Perhaps not, but I kind of think these approaches will rely much more on AJAX than on paging.