Long Term Security of Truecrypt's hash function?
Unlike the ciphers, the hash algorithm is not used directly to protect your data. Its only purpose is to take your ASCII passphrase and mix it up, shrinking or expanding it to the size required by the underlying ciphers. In order to make brute force attacks more infeasible, this process is repeated thousands of times in an algorithm called PBKDF2-HMAC so that each password attempt takes time. Because they are not used to directly protect your data, it would not be a major problem if the hash function were found to be weaker than believed. In fact, if your password was strong, even using the infamously broken MD4 algorithm would be technically acceptable, although it would be a rather nasty cryptography faux pas.