I think the technical highlight was seeing Adobe's Flex and Apollo in action. Truly impressive. Salesforce has also opened their API for mashups and created their own language, APEX, run on their "cloud" that developers can use. Their idea is to create a high value platform on which business applications can be built and communicate with other business data. Google was there as well, demonstrating how to connect salesforce to Google apps.
Salesforce currently has over 600,000 paying subscribers at a price of $60 to $250 per month per user, with some very large companies that have up to 20,000 plus users. They do plan to profit heavily from developers that work with them, from 10% of any subscriptions by app exchange developers, to large costs for exhibiting at their conference, etc.
One of the featured speakers at the event was the CEO of a 6 person company in Toronto that develops exclusively for Salesforce's app exchange. They are currently in line for making 2.4 million this year after bringing in 1 million last year. Of those 6, only two are in the same location. He owns 100% of his company with no outside investment.
There is no doubt that a seismic shift is taking place for businesses using web applications instead of supporting their own IT infrastructure. I think this is similar to the Lotus 123 explosion with PC's.