Not a whole lot in all honesty. Obviously some of the skills have changed and/or disappeared, and some of the monsters might have different CRs now than in 3.x (not sure on this), but PF is really close to being D&D 3.75. I would simply suggest being willing and ready to adjust your plans should you find things are going either too easily or too difficultly.
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+2 CR may not be enough for most encounters, unless your enemies are adapted to overcoming the massive resistances. The DR 10/magic andsilver is massive. Unless they're hunting vampires, almost no enemy will have this at the ready. Vampire characters are friggin powerful, moreso than a +2 CR indicates, given the ability score boosts, bonus feats, DR, resistances, and the horde of other abilities.
Alternately consider using the Dhampir characters (+0 level), essentially half-vampires. The supplement you or a player can invest in provides archetypes, feats, and equipment for the 4 different dhampir variants, allowing your players to enjoy the feel of vampirism without the severe imbalance. You may wish to provide a house-variant, such as being damaged by sunlight, to make them "more" vampiric.
If being a vampire makes the characters powerful, they are going to need a good reason why they would want to be cured. You may want to think of a plot other than looking for a cure.