If your equipment is all IPv6-capable, you may just need to have swap out your modem. Time Warner Cable has achieved 100% IPv6 availability (possibly excluding certain phone customers):
http://www.timewarnercable.com/en/support/faqs/faqs-internet...
http://www.timewarnercable.com/en/support/faqs/faqs-internet...
Before you suggest DDNS, for some companies, the length of unavailability between a changed IP and the DDNS client noticing and updating can be fatal.