DH and I stayed in a Savannah View room for our honeymoon in 2004. It was great for us, because we are insane about animals. We love them, and loved being able to wake up and see giraffes, or watch the tommies grazing in the dark before bed. But no matter where you stay in AKL, you will enjoy it. The theming is ridiculous, IMHO the best on property. And there are multiple places to watch the wildlife from that are easily accessible - and were never that busy when I was there.
You can try for a free upgrade, but don't hold your breath for it, especially for next month, since May is when the crowds really start to build. I would suggest as soon as you check in, make a comment about an upgrade like HagansMommie suggested. If that is shot down, then politely request a room closer to the lobby or close to an elevator bank. My Savannah View room was a really, really far walk from the lobby, hard after a long, hot day at the parks. But a room too close to the main areas might be a little loud. The Ostrich Trail area of the resort has some rooms that overlook a small savannah, and are not too far a walk from check-in. You might want to check if there are any rooms available there. And, don't forget to call now with your room requests, so that they are on file when you check-in, but remember that if you request a specific amenity (ie: king size bed) rooms like this are sometimes all in one part of the resort. Smoking Savannah rooms seem to be the furthest away.