The Gasman: bowtie is pretty neat, but otherwise, fairly bland.
Special Delivery: if they implement the extra damage from the rear with the short stopper it could be very interesting. milk+hat are alright, and the mackerel is awesome for comedy value and the plethora of bad puns that will inevitably ensue its usage :>
Croc-o-Style: very cool aesthetics. I hope the new rifle plays out as a whole new weapon (somewhere between the huntsman and the standard sniper, maybe?). that said, the other sniper pack that somebody designed (the moby dick one) featured the most worlds most badass crossbow/harpoon crossover, so I'm disappointed that it didn't make it instead.
Tankbuster: loving the cap. other than that... well, there's a hint that the new backpack might have a different use to the buff banner, but unless they stick some interesting stats on the rocket launcher there's not much to get excited about.
Saharan Spy: DAT FEZ. TF2 has been crying out for a fez for ages. not so keen on the sunglasses that they come with though. and look at how beautiful the revolver and daggers are.
look at them! those are properly classy lookin' implements of death. mmmmmyeahhh
in the end it'll come down to what the new stats are, but on the whole there is some good stuff, and a few really standout items, but a good deal of 'meh' aswell. and I am a little disappointed that my medic didn't get any new toys to play with. but we can't complain - in a world of paying for additional content, TF2 just keeps on giving at no extra cost, and this stuff is far from horrible.