Yes, MegaTokyo would be considered Amerimanga. Heck, all it means is an American comic in the manga style. In that respect, MegaTokyo is in many ways closer to the style than a lot of American manga.... well, not that that makes it necessarily better.
As for the other comic they were considering, I was very happy to hear that it was
Van Von Hunter.
If you are skeptical about Amerimanga, you should check it out... well, just so long as you don't mind that it strives to be frickin' hilarious rather than dramatic. And the art is among the best manga-style art I've seen from an American artist. It's no wonder TokyoPop picked them up. And in any case, the studio had already been previously published before they started doing Van Von Hunter.
Personally, I think the choice to include American manga is very sound. Japanese manga not only tends to conform to genre standards... it also caters to a
very specific cultural perspective. People tend to grossly underestimate the importance of this. Syndicated comics - heck, even most webcomics - are made to communicate at a very personal level with a specific culture. That's largely what makes them comics... at least, when you're talking about the kind that can be found
outside a specialty comic store.
Basically, if you want to connect with your reader in 4-8 panels, 7 days a week... well, you generally have to make a large amount of assumptions about what they know.
Just take a look at some of
our classics: Calvin and Hobbes, Bloom County, Doonesbury, etc. They all find ways to connect with the reader that would probably lose all humor & empathy value when removed too far from their native culture.