Hi,
Yes, you can still establish a IPSec VPN tunnel from SMB routers to Enterprise routers.
My best suggestion for you would be to call into the Cisco Small Business support center at 1-866-606-1866. We can then open a Service Request for you, and conference in Enterprise support. Together the SMB and Enterprise techs can get the VPN working.
Thanks!
Dave
David L. Barrett, Jr.