AHHH, the old Sherberth Road shortcut. Here it is step by step. We lived in Indian Ridge just past WH so did this a lot. If you are a little obsessive and want the very shortest route here is my opinion...
To get to ALL PARKS but Animal Kingdom I do not think Sherberth is quicker with new entrances unless it is very very crowded on Old Lake Wilson and traffic is way backed up there. From WH go up Old Lake Wilson, stay in right lane. Turn right on 192 or if deliciously obsessive turn right into the steakhouse driveway about 100 feet short of 192 and cheat down to their exit drive and go right on 192. Take first Disney entrance on right to get to all parks but AK.
To get to AK or AK lodge here is the slickest via Sherberth. Take Old Lake Wilson past Lexington Ave. and look for the BACK side of the Westgate Resort sign and turn left just past it. It will be a little tricky the first time...go for a short way and just before entering Westgate turn right at the fountain onto Entry Point BLVD. Stay in right lane and go straight across 192 in less than a mile. You are now on little ol Sherberth...it goes straight and then does some fast curves...(On the straight part look carefully right down the road and ask the kids if they can tell which tree is The Tree of Life in AK) Do a couple of turns, turn right at the stop light (Osceola Parkway) and AK turn in will appear on your left in less than a mile. Rest of the parks are another mile or so and then left turn at small single lane stop light.
To get back to WH from anywhere in Disney (and always exit the parks via Sherberth because getting out is easier than getting in) follow any sign to Animal Kingdom. Be ready to take some quick right turns off the main roads in Disney. As you approach AK stay LEFT to AK Lodge. Left at stop light onto Sherberth, straight across 192 onto Entry Point Blvd...at Westgate go 3/4 around the fountain and out to Old Lake Wilson and right to WH...Twice and you will be an expert!!!
Good Luck and have a great time...Ted