Fortunately there are 'only' 65k ASN's, thus that would mean only 65k routes in the routing table, which should be quite practical. Seeing only ~650 routes now I don't see that happening that soon, especially with the slowness of deployment of IPv6 in the US, though it is catching on ;). Left to wonder though what happens when we run out of ASN's, 32bit ones?
32bit ASNs are already in the works. I would expect not more than 2-3 years before you see widespread 32bit ASN code in routers.
As those policies are decided upon by the membership, feed your input to ARIN/RIPE/APNIC/LACNIC...
My RIR is ARIN, and, I am an active participant in the ARIN process. However, my comments on this issue started because I believe ULA will make ARIN or other RIR policies regarding allocation virtually irrelevant because economic pressure will drive ISPs to globally route ULA prefixes, which allocation is not controlled by RIR policy. Owen -- If it wasn't crypto-signed, it probably didn't come from me.