+1 to everyone for not turning this thread (yet!!) into a slanging match :-). as noted earlier, the main similarity if you don't examine the actual concepts is really just the <% %>
tags. you should really set it up on your machine and run thro a few of the basic illustrative samples to satisfy yourself as to the similarities or otherwise once you get going.
like a few above, i came from the vb6/com backgound and in my 'classic' asp sites (mainly intranet in those days - 8-10yrs ago) i used com classes and a data layer. When asp.net (v1.0) arrived i was sceptical about the benefits and it was defiantely a year or so before i took the plunge into that. once my feet were wet in the webfroms world, i was overjoyed at being able to 'port' my conceptual understanding of classes and BLL/DAL layers over to c#'s framework. my pivotal moment was prolly the publication of marco bellasco's asp.net 2.0 book 'the Beerhouse'. this crystalised everything that i had been (poorly) aiming at in my projects. fast fwd 5 years and the same epiphany moment arrived with both steven sanderson's book as well as the obligatory 'nerd dinner' series. I was a complete convert to mvc (and had been using it after a fashion in php with joomla). here i was able to leverage all the good stuff i'd learned re BLL/DAL (only in this case, the DAL was now a repository layer and the BLL the model).
In a nutshell, it's a very personal decision. all i can say is that having been involved in all the aforementioned technologies in production environments, for me MVC really has been the most productive and conceptually, the simplest to grasp (maybe in part due to my 'path').
your own mileage (or kilometerage :) may of course vary - but in a nutshell, read the pros and cons but ultimately get down and dirty with it and share your guilty secrets with the community once youve uncovered the 'beauties' of mvc'ing ...
good luck
jim