What you're talking about is web-apps, they already exist <img src="smileys/smiley17.gif" border="0" align="middle" />
Every now and then you'll hear stories about how web-apps are the future because they circumvent Apple's developer agreements and percentage cut, don't require a wrapper etc. Sadly this just isn't the case, it's awkward to handle payments for web apps, and apps sold in store get exposure, it's very hard to get that with a web-app, in fact I haven't met a single person in my life who has ever used a web-app!
Currently I use web-apps for prototyping, you can save the web-page to your home screen, so it even looks like an app!