I recently updated my online (watch only) to 0.92. When I attempted to create a transaction and sign it with my offline armory (0.90), it told me it must be updated (incompatible).
I updated it to 0.92 using "armory_0.92.1_ubuntu-64bit.deb", downloaded through the online client. No offline package was needed so I guess the dependencies were ok.
I'm still rocking 0.8 on my offline computer, I've yet to need to sign any transactions yet, although, I have generated a few wallets on the offline PC and brought them online (Watch only). That sounds like I'm going to have a huge pain updating. Gahhh.
I'll probably just dd the HDD and use the paper wallets to recover the wallets, transferring files is a pain.