Mobile Web expert Rudy De Waele has posted slides of a presentation he did last week in London, at the Mobile Web 2.0 Conference. This is the best and most comprehensive overview of Mobile Web startups and product ecosystem that I've yet seen. I particularly liked the following slide, categorizing the main players:

Check out the whole set of slides below, for an overview of Mobile Web startups and big company activity (e.g. Google acquiring GrandCentral in July this year):

Note: for a full-page view, go to the Slideshare page and then click "full" in the bottom-right corner.