i'm sure that apple has already researched the technical side of devloping a web browser at least a little. plus they have the mistakes and triumphs of all the other browsers and their history at their disposal.
i wonder just how much a browser by them would upset microsoft... just as long as it's ONLY available on the mac platform. appleworks, mail, and itunes all compete with microsoft products and there hasn't been much of a problem.
and it's not like microsoft spends a lot of effort on the mac ie. for some reason, they decided to make it work and act completely different than the windows version. my two biggest gripes being that you can't choose where inside your favorites to add a new bookmark, and it caches everything into one big archive file. so i'm not able to go in and delete this one file or copy this one file. VERY much a pain when testing new html.
and for that reason alone, it would affect their effort to dominate web development, since after all most sites are optimized for windows ie, then netscape 4.7, then maybe mac ie.....
in order to be successful, apple would need to develop a browser that worked with html, asp, php, etc in the same manner that windows ie does. that, if anything, helps microsoft...