|"Refine Your Skills"||41.4|
|"Fire All Lasers"||17.4|
|"Duty, Honor, State"||16.8|
|"Plug and Play"||13.1|
Unsurprisingly, two +4 skill implants are the most valuable gift, ISK-wise. In particular, they dwarf the value of the full +2 implant set. If you are considering the +2 implant set as your gift, you're better off taking the two +4 implants instead, selling them, and buying yourself two or even three full +2 implant sets with the proceeds. gg CCP, gg. ;-)
I've judged the ISK value of the skill books as negligible. Whenever CCP gives away skill books for free (as they did with the new tutorial missions last year, for instance), the market for that skill book almost instantly crashes. I expect more or less the same effect here, at least for the short term. The value of the various cruisers fluctuates a bit from day to day, but overall the value of any of the "cruiser" gifts is about 17 million ISK. As a result, it might be advantageous to take the two +4 implants even if you want the cruiser set. Again, you can sell the +4 implants and buy twice as many cruisers and the (suddenly very cheap) skill books with the proceeds.
Between the +4 implants and the "cruisers" are the "drill bits", actually apparently 160 tech 1 mining crystals. Mining crystals reprocess into Nocxium, the value of which is somewhat in flux. However, it seems clear that the value of these crystals based on that will be 25 million ISK or more. And between the impact of the drone alloy nerf and Hulkageddon, we could see the value of Noc rise substantially in the coming weeks. As a long-term investment, the mining crystals might be your best bet.
Or they might not. The "Paxist Treasure" gift is just... odd. I've written about the Pax Amarria before. As a "collector's item", this item is completely worthless. Literally hundreds of thousands of this item are available for sale, right now, from NPC sellers. If you want one, go buy one right now.
Still, its prominent placement in this dev-blog strikes me as very strange. Inferno is going to be -- by definition -- a very war-focused expansion. The Pax Amarria is the written opposite of that intent. It might (and I stress that word might) be CCP's plan to make the Pax Amarria a collector's item by severely restricting or eliminating the supply through some sort of in-game action combined with the cinematic trailer for the expansion. The Minmatar destroy the original copy and cause a virus to destroy all the current versions in the hands of players, perhaps? If that's the case, the Pax Amarria's NPC sellers might quickly run out, or the NPC sale price be greatly increased.
It strikes me as an unlikely move -- CCP's few recent attempts to drive trailers with the lore of the game haven't been successful. Still, if you're looking to gamble...
EDIT (30/Apr/2012): Well, that explains that. CCP Greyscale says that this version (with a different spelling) will be a different item and will be "explained later in the week."
Whatever you select, enjoy your gifts!