Google will most likely smite you for setting it up like that, though. The fact that the ordinary user won't even be able to tell where links are heading to will mean a penalty of some sorts.
Chances are, more intelligent anti-virus software will blacklist your site, as well.
Lastly, your website will probably have a higher drop-out rate the more interactive elements you add. At this point, however, your site still manages to load way quicker than that Clikpic crap a client of mine keeps using.
I've considered adding a few splash screens of some sort, but am kind of weary of adding another iFrame, since the first (albeit hidden) one already scrutinized my ranking.