So BB Connect for E90 will install on the E71 - with a few slight modifications. It will not properly submit a registration and PIN request. So to install BB Connect on your E71, you can follow these directions.
Firstly, you'll need full FS access+patched installserver on the E71. You can do this using HelloCarbide on original firmware or HelloOx on 200.xx firmware. Sign it and install it, it's really that simple. You will need a certificate with 17 levels of TCB access to sign it; email me your IMEI or visit http://cer.s603rd.cn/
Next you will need ROMPatcher with autorun feature and the C2Z patch. Move the C2Z patch to E:patches. You will also need to move sw.txt into C:RESOURCEversions - this will identify your device an as "E90" when the BB Connect installation is being completed.
Now that you have completed this, you can install BB Connect for E90 by using ROMPatcher to enable C2Z which will cause a re-direct of certain files normally stored in Z: to C: which you now have full RW access to.
Open the BBConnect SISX and install it. It will complete and ask you to turn on BB Connect. Do so. Check your HRT and enable that you have access to the BB backhaul and a blackberry.net APN. Attempt to register by selecting the left soft key and clicking "Register Now". Nothing will happen. This is being investigated.
If any of you have an E90, wifi and know how to work a packet sniffer, I'd appreciate if you contacted me to see if we can force a request packet to be processed.
http://www.mediafire.com/?sharekey=b0a9396d79079a53d2db6fb9a8902bda has a zip with all required files.