cbg, don't think that will happen any time soon. Although, there had been some discussion when the SAT folks had all of those testing problems in the past few years (coupled with the revamping of the test to 3 sections instead of 2), that seems to have tabled.
Colleges/universities do all consider them slightly differently, however. That is to say, some require and consider all three portions of the SAT, many require but consider only two (excluding the writing portion), only some require SAT IIs (previously known as subject tests), and one (Princeton) still requires 3 SAT IIs, all others require two. Just about all will take either the SATs or the ACT. And next year, just to make things more complicated than they already are, the SAT is instituting a new "rule" - they are following suit with the ACT. You can now select which of the SAT test sittings you wish to send (previously, once you sent an SAT score to any college, all of your test sitting scores went along with).
As zomby suggests, it is a good idea to sit for either or both exams twice, as expert evaluation shows that scores will likely improve in a subsequent sitting. Not to mention the fact that if you score about the same, it shows the college/university that your marks are consistent (in other words that really high score you got wasn't a fluke after all
) However, there is a break point where things do not get better, probably after 3 or 4 sittings.