"And of course, it's the fact that there ARE intelligent beings here and that the universe IS special that's so interesting, and in fact seems unexplainable by science."
You misunderstand. The universe is special, not because of any intrinsic characteristic, but because we (the intelligent beings) believe it is special. Also, the fine-tuned nature of the constants is not unexplainable; it just hasn't been explained yet. There is a difference.
"This statement seems to describe the universe itself as a thinking entity that 'needs' to create intelligent beings and places constraints on it's own physical constants to do so."
Not really. This is another of those counter-intuitive ideas, but the SAP does not necessarily imply an intelligent universe (though some versions do). It simply takes the WAP one step further to say that if intelligent life is needed to make the universe "real", the universe will order itself in whatever way necessary to create that life.
"I'm familiar with the oscillating universe theory but according to the last reading I had done there was no scientific evidence for it."
That's not the problem. You wouldn't expect any evidence to survive the Crunch/Bang cycle. The real problems are as you stated: is there enough mass to close the universe and will the Big Crunch rebound into a Big Bang. The jury is still out on the amount of mass that the universe contains, as long as there is still a possibility for cold dark matter. As for whether the Big Crunch will rebound into a Big Bang, the models say yes, if the universal mass is sufficient.
"What is the baby universe theory?"
The theory is based on preliminary attempts to combine quantum mechanics with general relativity. The models so far devised describe the state of nothingness as typified by a vacuum as an inherently unstable condition filled with latent energy where neither space nor time as we understand the concepts exist. One can thus visualize a vacuum at the Planck level (10^-33 cm) as being a writhing foam. One prediction of this visualization that has been verified is that normal space-time vacuum can produce what are called virtual particles. For about 10^-21 sec an electron-positron pair can simply appear out of nothing, then disappear again. Very, very, very occasionally, however, one of these particles doesn't disappear. The nothingness before the Big Bang might have been energetic enough to create virtual universes, with the occasional possibility that these baby universes rapidly expand into full-fledged universes instead of simply disappear again.
"Is there any research to support this theory?"
Yes, but not the kind you're probably thinking of. At the risk of setting off the cosmologists in the group, cosmological research consists primarily of playing mathematical "what-if" games: if conditions were like this, what would be the results? Whenever these games make testable predictions then secondary cosmological research - in the form of examining the universe we know of - can be done. These games have proven very successful, however. One of the first two, relativity and quantum mechanics, led the way to the Big Bang, electroweak, grand unified and inflationary theories, to name a few. Attempts to combine quantum mechanics and relativity are leading to a theory of everything, hyperspace and superstring theories, as well as a possible verification of wormholes and loopholes that will allow superluminal communication and travel. What determines whether these games are successful are primarily whether they are logically consistent and can accurately predict the current st
ructure of the universe, and secondarily whether they make testable observable predictions.
"But are there any methodological restrictions on scientific theorizing that prevent postulating the existence of a universe we cannot possibly measure as a way of explaining date we can measure?"
Only if your reason for postulating the existence of another universe is to explain the conditions of this universe; that would be ad hoc and so unacceptable. But if the postulated existence of other universes is a prediction of some model unrelated to the question of the conditions of this universe, and if that model is logically consistent and makes other successful predictions, then you can legitimately use its postulates to explain mysteries in other models.
Kevin L. O'Brien