One of my first web framework was a custom one, based on the book Web Development with Java Server Pages. That was in 1999, when Struts was not yet known. But it was web-MVC, very near from what Struts gave later, without the custom tag stuff (custom tags were not yet part of JSP specifications).
Until 2007, Struts was IMHO the most used web framework and the default choice, even though many contenders appeared, with more features, better code. 2007 saw the maturity of some of these framework. As similar framework to Struts, I particularly like Stripes, because the API is very lean. Some component frameworks got a lot of buzz as well, Tapestry some time ago, and today Wicket. I tried both, and while they are very interesting, and can be very productive for some tasks (web application more than web site), I am not convinced they are the tech of 2008. Web Applications are better done with Flex, or GWT.
The major news in the past few years has been Ruby On Rails. Everybody tried to replicate it in every language (with their own twist): Django in Python, Lift in Scala, ErlyWeb in Erlang, Cake in PHP, Grails (along with now abandonned Sails, and less populair Trails) in Java. And some people fought for making the point they had the idea before Rails. But Rails is what made Rails-like development popular.
After trying Rails soon after it was out (way before 1.0) and more recently (just before 2.0), I was amazed by the progress of Rails. I was impressed in 2004 about Rails, because the approach was new and effective. I disliked a bit the choice of Ruby. In the end in the project we ended up rewriting the persistence layer because our application was very specific. And I ported the app very quickly to Java. In 2007, I was even more impressed, and did not need to dwelve into arcanes of Rails anymore, but merely using it was enough to do lots and lots of things.
In 2008 the Ruby On Rails mentality will continue to prevail. In the Java world, Grails is the most likely to benefit from it. But I would not be surprised if there was another new Rails-like contender in the game (Rails on JRuby?). It could also be something based around Spring as their current MVC solution is not very good and very old fashioned.