It depends alot on what you are looking for, and the age of your family. With only two days, younger kids are going to spend much of that time in MK, while older adults would be likely to want to visit Epcot for the Flower and Garden Festival, which is fantastic. Teens and young adults will want the thrill rides at MGM.
If you try to cram all four parks into two days, you'll miss alot in each one. Younger kids would never stand up the the incredible pace you would have to set trying to experience four parks in two days, especially for the first time. (For that matter, neither would adults!!) Perhaps it would be better to pick just two parks for this visit, and save the other two. If you picked just the monorail parks, you could park at the TTA in the morning, and take the monorail back and forth between MK and Epcot.
If you parkhop to MGM or AK, you'll spend alot of time just driving, parking, and tramming in.
Whichever you choose, be sure to be at whatever park you choose each day for opening, as you can get more done the first two hours of the day than other other ten hours combined. Also be sure to use Fastpasses.
You've got your work cut out for you. My best advice is not to knock yourselves out trying to do too much. Take the time to smell the flowers, and really enjoy the time you have rather than going at a dead run trying to experience everything in two days.
Good luck, and I hope you have a wonderful time!!
