The point Dave missed is that Google for example doesn't really want to open its infrastructure to outside users, they consider their infrastructure and scaling ability to be a key competitive advantage.
They want the walls in place, the walls limits the list of their potential competitors in their key market of search.
The problem is that once one big player releases a service or technology that start leveling the playing field, your only choices are to join the band wagon or be left behind.
That's true to a degree. However, Google also follows the mantra, "what's good for the Internet is good for Google." For example, they provide the monetization system (ads) to ask.com, which is a direct competitor. Why not also provide compute clusters?
I think Google and Microsoft are asleep at the wheel while Amazon is forging ahead becoming the leading provider of internet infrastructure for the next generation of startups.
They want the walls in place, the walls limits the list of their potential competitors in their key market of search.
The problem is that once one big player releases a service or technology that start leveling the playing field, your only choices are to join the band wagon or be left behind.