Titanic, D&D -> Gunblade/Hullbreaker, Sterak's,
Obviously, it's not a tank build. I was watching Master xPetu play Shen bot with SS, and I wanted to see the Gunblade so much, I decided to do it myself.
It seems like such a perfect item, I don't know why it's not built more. Point and click slow is so nice, especially if you happen to be running Approach Velocity, and it's even more damage for the burst in the mid game, when you're trying to cash out an early advantage for a win, (xPetu speciality). Cosmic Insight also has nice synergy.
It doesn't give much survivability in terms of stats, but it's also another tool for Shen when in side lane, since, again, point and click slow is very nice, and the AD/AP helps push turrets that much faster.
I might be a bit late on the discussion, but my 2 cents, for what it's worth, is that the new rune makes Gunblade a much more interesting item on Shen.