According to Google maps, its about 1.1 miles from the front of Jambo House to the turnstiles at Animal Kingdom Park. Even if Disney was to construct a special walking path, I don't think it could shorten the length much due to the layout of the savannas surrounding much of AKL.
Frankly, I don't think the vast majority of guests would use a walkway between AKL and DAKP. 1.1 miles might not sound like much, but keep in mind that the BLT-MK walkway is less then 0.5 miles and the Hollywood Studios to Boardwalk Villas' side entrance walkway is about 0.6 miles. Summertime heat, humidity, and rain storms would discourage a lot of guests -- especially those with kids -- from walking. Add in the fact that AKV-DAKP buses usually make the run in about 10 minutes, I just don't see a AKL-DAPK walkway getting much use.