Just for clarification:
Under PEFA the donors are scored according to the regularity of delivery of Budget Support - a nod towards predictability, which of course is a tenet of Paris/Accra. However, I suspect that donors are moving away from Paris / Accra at present and, as noted in other posts, will return more to project aid and greater conditionality - sad but true, and no doubt a reflection of both the current economic climate but also the ineffectiveness of GBS in countries with weak/corrupt institutions.
As for the point about decentralisation, again a noble thought, but the confusion here, is that often the ultimate arbiter of Aid is the Ministry of Foreign Affairs (HQ) - a political beast that will want control aid spending according to political priorities. Last year, the Swedish Zambia office was keen to continue disbursements of aid despite the uncovering of significant corruption in the ministry of health involving their (and Dutch) funds. They were overruled by HQ - the ultimate arbiter of policy, and, I might add, the custodian of their taxpayers monies. I can't see this decentralisation happening for large amounts of aid.