The most obvious two that could have killer iPod Touch-like products are Palm and Google (Android):

1. Palm's in trouble with just its phone. It seems like they have to figure out their webOS phones first before launching something like this.

2. Google's problem is the same issue they ran into with the Nexus One. Google doesn't do retail. It doesn't like retail. An Android phone can easily be sold by the Carriers. Gladly. An Android media player, however, needs to be sold in retail. And that means offering things like a store, or agreements, and telephone support, returns, etc.

Apple, on the other hand, understands retail and does it well (see Apple Stores and website), as well as already have a killer phone on the market.