It depends on how old-school your company is.

Play Framework, while it is still using Java, breaks the old-tradition of getter/setter. Your peers might resist instantly when they saw that part.

If Play Framework is too extreme for your workplace, I'd suggest to give Spring MVC 3.0 or use the latest Java Servlet 3.0 in JEE6.

Java Servlet 3.0 supports annotations (http://blogs.sun.com/swchan/entry/servlet_3_0_annotations) that provides routing capability (might not be as powerful as Rails routing, but still something new and nice to try).

For ORM, either JPA 2.0 (recommended) or Hibernate (Hibernate specific APIs, not Hibernate as JPA 2.0 provider). But as with any ORM: you need to know it well (ActiveRecord is not an exception either).

Additionally, JPA 2.0 provides Level 2 Cache API interface: you can either write your own but conform with the API (the API is very simple) or use the one provided by the JPA provider.

Hibernate (if you use it as the JPA 2.0 provider) supports a variety of L2 caching solutions (SwarmCache, EhCache, OSCache, JBoss Cache, Infinispan, etc). Plug n play baby!

Play Framework is excellent for rapid web development. The edit/compile/run cycle is very short. Just like PHP, make a change in the Java file, refresh your browser, and the compilation/deployment is done right the way automatically.

The URL request routing and handling is straight forward and powerful. Request parameters are mapped to Java objects automatically. The Groovy-based rendering template engine is very simple and powerful.

Play employs the easy to use JPA by default for DB backend layer but can use other frameworks easily. In one project I've used the JPA to interface with Oracle. In other projects I've used the Objectify library to access GAE's NoSQL Datastore when developing Play in GAE. Both work great.