Did some major catching up on Heroes Season 3, having a ball with the characters still. There are comics and all manner of other bits and pieces of course. Check out HeroesTheSeries for lots more. I like the artwork that actually plays an important part in the series itself as well and the integration of the comic into things as well is very cool indeed - reminds me of the Watchmen.
Isaac Mendez paintings were done by Tim Sale, though now we have Parkman and others delving into the future this way and so we may have other contributors.
[a few of the art/sketch pieces used in the Heroes series via shellscript.co.uk]