How odd! I checked here and on Sprint's twitter feeds but I haven't seen any communication of the form either:
"Hey Hero customers, you may have seen the Eris is being updated right now... and that means your virtually identical phone is also ready to be updated and your long wait is over! You can expect it to be available on 5/xx/10!"
"Hey Hero customers, you may have seen the (virtually identical) Eris is being updated right now...but we're deeply sorry to have to ask for your continued patience. Your update is still not ready and still has no release date BECAUSE [fill in lame reason for ongoing delay here and for crying out loud don't mention the NASCAR app!]."
I'm sure someone is just working on the wording before posting.