The idea is great, but I see some difficulties:
– There are no tools on the market and development will take more time
– Presentation will be mixed with markup. Sometimes this is not a big deal, but potential problems are there and maintenance may take more time
– The Ajax technology by itself is new, team will have to invent new ways designing application and this bleeding edge activity will definitely take more time.
So I don’t think many companies will adopt Ajax during the next few years. Time to market is critical and choosing Ajax putting any project under the serious risk. However, when the approach matures and some development tools appear – the technology has a chance to become a mainstream. We will se.
Very good link re: Ajax – examples, frameworks and articles