wrt. Spring and Hibernate:
I dont know exactly how widespread their use are, but I have noticed
they are gaining popularity and in the last project I was involved in
Spring was used throughout.

A trend I noticed is a slight move from heavyweight systems such as
Struts, Bea etc to more lightweight systems built upon 3rd party
libraries such as spring, jakarta libs etc and other more efficient
utility libraries such as trove etc.

To answer your last question, yes I definitely think that Spring or some
derivative of it will exist for a long time.

/tom

I have serious production systems deployed based on Hibernate.  I
recommend spending more than just a few weeks with it.  It can take some
effort to map an arbitrary set of objects to an arbitrary db schema, and
it can be practically impossible if you are not in control of either the
schema or the mapped objects.  

Spring can be a monster if you're not already familiar with J2EE
development, meaning, if you haven't run into a lot of the problems that
Spring seeks to solve, or, not exactly "solve", but collect under its
umbrella of abstractions.

Frontend stuff like Velocity and JSP aren't really my thing.  I do a lot
of business infrastructure work, and I'm sure I could benefit from
Spring, but I don't use it.  I don't think "the hard way" is all that
hard, so something like Spring would add complexity and constraints
where they aren't needed.

I'm a heavy user of hibernate though.  It's not without problems, but it
definitely helps me make the data binding layer abstract.  I work with
big db schemas, multiple databases, and lots of binding objects that are
auto-generated.