The assassin spells in 3.5 were too little too late, you were looking at gaining (1st level) spells three or four levels in to the class, and that's after the five or six prereq levels. I'd much rather have some nifty abilities than a few niche spells.
I like the new PF assassin better, but I still don't know how well it'll hold up next to other classes. The death attack with no wait time is a good thing, though it's only once a day, you have to sneak like a creep, and the (usually) low save for it makes the death attack almost useless in high level adventures--unless you were playing an urban adventure and the player was picking on poor 0-level NPCs.
On the other hand, an old red dragon rolling a 1 against a death attack might make all the other shortcomings worth it.
P.S. oh wait, blindsense. Nevermind.
Post Post-script Blindsense evasion would be a neat ability for the assassin, though arguably not fitting to the flavor of the class.