I signed up for datasheet service and newsletters via email at the most common chip manufacturers.
Especially NXP publishes revised datasheets that way.
Concerning Eagle packages I'll be happy to post them here for everybody's use and convenience.
Having designed more than 1,000 new packages for Eagle usage I've developed own efficient techniques to make a package accurate to 1/1,000mm. (Won't work with Eagle versions later than 3.55!)
Chip manufacturers come up with different designs of packages increasingly, e.g. for the already known SOP package they are now using SSOP packages (Super-SOP, completely different in body size, pin spacing and length)
Boncuk