Assuming a certain context for mobile device interactions is often wrong, but it’s only fatal if no way is provided to view the full experience. The beauty of smartphones (as heralded by the original iPhone) is access to a browser capable of displaying complex web pages in a smooth, usable way. Go ahead and make that mobile site optimized for a specific use case. The more access you have to your users’ true context, the better it will be. Just don’t forget your assumptions may be incorrect. Always provide an escape route.
The link that spurred this miniature post: The Mobile Context from Mark Kirby.