I'm not terribly interested in winning. I don't have a dog in this fight. I'm simply replied with a benefit of RW over iWeb because you said you were looking for a replacement.
Quite frankly, if you're happy with iWeb, there really isn't a compelling reason to give it up yet. I wouldn't let the EOL thing scare you away. It hasn't really been advanced in 3-5 years, aside from a few built in "widgets" that were easy enough to implement as HTML snippets. They didn't even add any new themes in the last release.
But, to answer your question: I probably wouldn't. Personally, I've never been a big fan of the look of photo albums in iWeb. I always linked to my MobileMe Gallery instead. Now that those are gone, and I'm actually selling prints/downloads, I like to a Zenfolio account. I couldn't consider something a little more modern, using some kind of Javascript/Ajax lightbox type of code.
But if I really wanted to emulate the iWeb albums, I'd look though the plugins on the Rapidweaver site. I spent about 30 seconds there, and found one that is similar:
http://www.smackie.org/software/rapidalbum/
In the "demos" section, select "Galleria". It's not a perfect replica, but somewhat close for 30 seconds of searching. Look around, you might find something that's a closer match, if you're interested in going that direction.
Here's another one that's along the same lines:
http://symfonip.com/products/gallerybox.php
There's also some really cool stuff in Fancy Image Stacks:
http://joeworkman.net/rapidweaver/stacks/fancy-image-bundle/
You can buy one effect, rather than the whole bundle.
But, in the end, if you really like iWeb, I see no compelling reason to switch.
I hope this helps.
----------
Also, if you upload your photos to other places (Facebook, Flickr, Picassa, etc.), there are plugins available that allow you to automatically include those photos in the albums on your site, without having to manually upload them to both places. I've never used one myself, but I've heard good things about them.