According to this, finishing last gave you a 48.2 percent chance of picking first, at least in 2011.
I don't have a huge problem with that much of a chance for the number 1 pick, since it's a guarantee that a good team that happened to have a bad year will under no circumstances land someone like a McDavid or even an Eichel.
Doh, apologies you are correct on the total percent.
Still, wrt to the "good team/bad year landing a super star" concern, I would rather there be a random chance of that occurring (even if it's more likely, it's harder for a team to shoot for it), then a pretty heavy mathematical advantage to tanking. In the old and current system you are still guaranteed to finish no worse then second. I say re-seed all non playoff teams with those new tables for the first round, but this change is pretty good too.