Security of the network and the idea of there being a network in the first place, depends on how many full nodes there are, how diversely they are spread across the planet and how able they are to handle the load.
5 super-connected super-nodes with 8Gb blocks would technically still constitute a network, but I'm not sure if you want to call that Bitcoin.
We need to address the block size issue responsibly and re-evaluate network's health with regular intervals.
http://gtf.org/garzik/bitcoin/BIP100-blocksizechangeproposal.pdf
I too still sympathize with the idea of one-off fork to 8Mb. Clean and simple.