I don't think that there is any need to wait.
10 GigE is still pretty expensive compared to 1 GigE. The new Cisco Nexus 5000 switch is still running at about $900 a port. I don't think there is any danger in deploying now with a gigabit infrastructure. You should at least have 1 GigE, but there is no need to wait for 10 GigE.
By submitting your personal information, you agree that TechTarget and its partners may contact you regarding relevant content, products and special offers.
Check out the entire iSCSI SAN FAQ.