From what I understand, no hash function has ever stood the test of time as some block ciphers have. SHA-2 is of related design and although no one's found an effective collision attack yet, I don't think it would really surprise anyone if one were found. This was in large part the motivation for picking a SHA-3. If you use SHA-3, it's of unrelated design to SHA-1, but it's also much newer and hasn't gotten as much cryptanalysis yet.