Heroku, being top dog of the PaaS market, doesn't really have a lot to gain from being able to migrate. Being a market leader, they're already the default for many projects; a standard, easily movable, container for applications would quickly strip away the value they can add to a project. A commodity PaaS deployment platform would quickly drive prices down to nearly bare-metal EC2 prices rather than the high markups that Heroku currently charges.

Redhat's in an interesting position here. They've got a lot of capital & a strong presence in the enterprise but OpenShift is still a minor player in the PaaS market. They have the resources & the credibility to push an open container & give it credibility while also being in a position to benefit financially from commodity containers - anyone that moves from Heroku to hosted OpenShift is a win for them as is any company that goes to RH for their own cloud.

I really hope so, with the work that Red Hat and dotCloud are doing it will be possible for a Docker container to run on any Linux OS - which is a significant first step towards ubiquity. Whether Heroku's Buildpacks are then able to be layered on top of a Docker container is the question, not impossible as they are open source but will Heroku come on board? It seems Red Hat's OpenShift is making the moves towards this being possible with their cartridges which are the equivalent of the Heroku Buildpacks. The key bit is that the community seems to be converging around some standards that could lead to true application portability for PaaS, something we don't really have yet.