Comics editor Tim Beedle discusses on his blog whether or not it's necessary for manga-influenced Western artists to change their style in order to find work.
I chimed in with my experience as a professional manga-influenced comic artist. My full reply is below, but you should also go read Tim's post and the proceeding comments. The whole discussion is very interesting.
As a creator who was part of the OEL movement, this topic hits close to home. For me, manga had a heavy influence on my artwork during my formative teen years. My manga-influenced art style wasn't something I quickly adopted as a moneymaking scheme to dupe the manga-reading public, as some naysayers of the OEL movement believe, but simply a part of me, a natural expression of the material I grew up reading. An art style that was natural to me, intuitively picked up from years of reading manga, mixed with other influences, and personal touches.
For a while, it looked like the possibilities for manga-influenced artists were on the rise, until the manga market/economy collapsed. Then Tokyopop stopped taking chances on creator-owned properties, other companies followed suit, and the movement more or less died (save for the small handful of licensed properties -- good opportunities, but nowhere near enough to support all of the talented manga-influenced creators out there).
Following the completion of Peach Fuzz in 2007, I went from being a successful creator with a growing career, back down to the ground level, scraping around for jobs, painfully discovering that outside of the Tokyopop bubble, there are very few opportunities for comic artists heavily influenced by manga.
The year or two following Peach Fuzz, I received my fair share of rejections: art agents telling me that while my art is professional and solid, it's unmarketable due to a lack of jobs calling for a "manga" look; publishers and literary agents enjoying a story premise, but turning it down due to, again, the "manga" look. Eventually the message started to sink in: adapt or die.
The last couple of years, I've been working to tone down the manga influences in my artwork, but it's been a painful process. Some good has come from pushing myself in a new direction - I've definitely grown a lot as an artist because of it. For example, I've developed a new approach to comic pages that I'm very happy with (see Last of the Polar Bears). But it's also depressing to look back at Peach Fuzz, and the art style that came very naturally to me, that I've had to sweep under the rug and hide.
The thing that gets me the most, is that even though mainstream publishers are apprehensive about comics with a heavy manga influence, the kids and teens adore it. The amount of times I've had kids come up to me at conventions to tell me that they loved Peach Fuzz, or even that it was the first "manga" they ever read (!!) are too numerous to count. The kids don't have any innate prejudices against the material--all they want is fun, appealing stories to read. Give that to them, and they're happy--who cares whether your artistic influences are eastern, western, or both?
Given enough time, I'm sure more publishers will open themselves to manga-influenced comics again... In the meantime, should creators have to alter their style to make a living? Sorry to say, but at least for this creator, it was either that or find a new career path.