The first thing you notice about Skipjack is its simplicity. There are few design elements, and after some thought you can point to each one and explain why it is there. There are no weird constants. There are 32 rounds, and 32 rounds can hide a lot of faults, but the design seems sound. And very fragile.
Some algorithms are strong because they are of a strong type of algorithm.
Similar algorithms will also be strong. Make almost any modification to Skipjack, even a small one, and the result can be broken. I predict that the most interesting cryptanalysis work will come cryptanalyzing Skipjack variants. People are already attempting to cryptanalyze Skipjack. Mostly we've seen breaks of modified versions of the algorithm, together with explanations of why the attack won't work against Skipjack itself.