I've attended "The Evolution of PaaS" talk by Paul Fremantle at QCon. Here are my notes from the talk:
1. The are still problems we face in the application development teams: randomness (random libraries are used, there are random ways of doing things), project infrastructure takes too long to set up, we use unknown, unapproved libraries, there is no easy way to have a clear idea of which project is at what state at any given moment, there's too little automation, there are few or no metrics on code quality, test coverage and re-use. PaaS could give a way for fixing some if not all of those issues.
2. What it means to be cloud-native? To be distributed (works in the cloud), elastic (uses cloud efficiently), multi-tenant (only costs when we use it), self-service (in the hands of users), granularly billed and metered (pay just for what you use), incrementally deployed & tested (seamless live updates).
3. PaaS itself is a step in the evolution - either from IaaS (when you decide to start using services provided by PaaS in addition to infrastructure you're already using) or from SaaS (when you decide you want to enhance the services you're using more deeply).
4. PaaS is about taking what developers care about and making it self-provisioned, managed, metered and paid per use in the cloud. The developers care about the code, but also about tools outside of the codebase (messages, databases, logs, workflows) and about non-runtime "things" - svn, git, build, CI, code coverage, automated tests.
5. The evolution of PaaS so far was about moving from just allowing developers to deploy applications (they still need to care about what the infrastructure looks like) through speciation, expending services towards dealing with multi tenancy. PaaS will obviously be still evolving.
6. What it means to be open: open to run in different places, open to run on different IaaS provider, open to run different types of applications, open to new services, maybe open source? Types of PaaS right now: public PaaS (Heroku, Amazon Elastic Beanstalk), private/public (Tibico, Microsoft), open private/public IaaS.