According to Admob (via TUAW), Apple's share of the mobile Web is big and might just be getting bigger:

Worldwide requests from Apple devices grew 28% month over month to 1.2 billion in January. Building on its strong December, iPod Touch growth outpaced iPhone growth in top markets. The iPod Touch now represents 40% of Apple requests, up from 20% in September.

People like great mobile browsers that can handle HTML, CSS, and AJAX, who'd have thunk it?

Of course, competing devices from Nokia, Palm, and Google, are beginning to use Apple's WebKit in browsers of their own, Firefox keeps threatening to push their mobile Fennec client to release status, and RIM is inching the Bold towards usability, so can Apple and the iPhone/Safari team maintain their leading edge?