Yes, absolutely. If you're using JomSocial, Community Builder, or any of the other extensions we support with our Social Profile, that feature is already implemented. If you have your own forms, or are using an extension that doesn't currently have a profile plugin for it, then you'd need to add some PHP to the view for that page to pull the user's info and pre-populate it.
Let us know what extension you're working with, the type of form you're trying to fill out (registration, contact us, submission for something, etc) and we can give a little code snippet that should help. You'd still need to do some development on your end though.
Thanks,
Alex