Yes, I think in future we'll be splitting the concept of payment from the concept of bitcoin transaction so a single payment may actually be made using several unlinked transactions that move outputs of roughly the right amounts. The payment protocol work already takes us in that direction. It would close those kinds of privacy leaks although it'll make payments somewhat "soft" in that when somebody sends you a large payment, it might actually take a bit longer to completely arrive (as it'll be delivered in chunks).