It depends.
Junior players that first became draft eligible in 2004 should, theoretically, have been eligible to be signed as UFAs starting 7/1/05 (in other words, after they went undrafted in the HFNHL for two years).
NCAA players, on the other hand, don't become eligible to be signed as UFAs until the free agency period after they've graduated/dropped out.
Of course, I can't recall whether or not the new CBA changes any of this!