Wow...4+ years later and I'm finally posting part 2. Yep, the original config didn't work quite right but I did get it working. Here's the result:
On the Cisco switch:interface Port-channel98no ip addressswitchportswitchport trunk encapsulation dot1qswitchport mode trunk!interface GigabitEthernet8/5no ip addressswitchportswitchport trunk encapsulation dot1qswitchport mode trunkchannel-group 98 mode on
etc...
On the Extreme switch:enable sharing 1:1 grouping 1:1,1:2,1:3,1:4 algorithm port-basedconfigure vlan "out_of_band" ipaddress 172.16.0.254 255.255.254.0configure vlan "out_of_band" add port 7:1 untaggedconfigure vlan "out_of_band" add port 1:1 tagged
out_of_band was used for testing. I put a PC on port 7:1 on the Extreme switch to make sure I could get to a PC on the Cisco switch.
Turns out I did full documentation on the test process and actually kept the doc! I was amazed! My notes suggest the only delay was when re-connecting ports that are part of the group they would not start forwarding for about 3 seconds. Otherwise it worked great!