I know 2 now:
There many options for deploying play framework applications on the cloud
Like codemwnci said, most of them work with a war deployment.
Heroku for play!
princing: http://blog.heroku.com/archives/2011/8/29/play/ (seems like you get 1 web dyno + 5mb postresql db for free)
sample: http://devcenter.heroku.com/articles/play
db: postgresql
deployment: native via git
tutorial: https://github.com/opensas/play-demo/wiki/Step-13---deploy-to-heroku
play2 support: http://www.playframework.org/documentation/2.0/ProductionHeroku
Openshift
A PaaS offering by Red Hat
module: http://www.playframework.org/modules/openshift
pricing: you get 5 apps, with 500MB space each, for free, supports mysql, mongo, jenkins, perl, php, python and java
article: http://playlatam.wordpress.com/2012/02/09/play-framework-on-the-cloud-made-easy-openshift-module/
db: mysql, mongodb, postgresql
deployment: war deploy via git (or using the module)
(Using the raw cartridge is possible to deploy play apps natively, I'll see if I can write a tutorial on the next few days...)
vote for native support: https://www.redhat.com/openshift/community/content/native-support-for-play-framework-application
tutorial: https://github.com/opensas/play-demo/wiki/Step-12.5---deploy-to-openshift
Google Application Engine
module: http://www.playframework.org/modules/gae-1.4/home
cons: can't use mysql, should not use JPA
http://www.playframework.org/modules/siena-2.0.0/home
db: uses it's own datastore (Instead of JPA it is advised to use siena)
deployment: via module
nice example: http://viralpatel.net/blogs/2011/01/first-play-framework-gae-siena-application-tutorial-example.html
tutorial: https://github.com/opensas/play-demo/wiki/Step-14---deploy-to-gae
dotCloud
module: http://www.playframework.org/modules/cloudbees
princing: https://www.dotcloud.com/pricing/ (there's a free plan with 10MB db)
AWS - Amazon Web Services
pricing: http://aws.amazon.com/en/ec2/#pricing
pricing: http://aws.amazon.com/en/elasticbeanstalk/#pricing
samples: http://www.ibm.com/developerworks/java/library/j-javadev2-19/index.html http://www.ibm.com/developerworks/java/library/j-javadev2-16/index.html
Jelastic -
homepage: http://jelastic.com/
CleverCloud
homepage: https://www.clever-cloud.com/en/
pricing: https://www.clever-cloud.com/doc/clever-cloud-overview/pricing/
deploying for Scala: https://www.clever-cloud.com/doc/scala/play-framework-2/ deploying for Java (same?): https://www.clever-cloud.com/doc/java/play-framework-2/
There are lots of options, and new ones come out every day...
Here's an article with a list of the Public and Private Cloud PaaS for java: http://cloud.dzone.com/articles/regarding-java-platforms
Regarding play 2 support, heroku provides native support and once war deployment is ready (is scheduled for next minor release) you'll be able to deploy to most of them. I managed to deploy a play2 app to openshift using the do-it-yourself cartridge, here's a screencast and a tutorial)