I'm sure that there will be an upgrade to the existing TB display in 2013 - as it's about due dor an overhaul. The only things I forecast changing will be a slimmer design and USB 3.0 ports. If you can live without those, there's no time to buy like the present. I don't expect, at all, "Retina" TB displays - no GPUs save on upcoming Mac Pros could handle those graphics.
So if a slimmer design and USB 3.0 ports are tops on your list, don't buy the current model. No one knows when any new models will be announced - along with the new Mac Pro, I would imagine - so it's anyone's guess as to what will be new in 2013.
You did help to a degree but as I described in original post there are many complaints about TBD that are left unanswered which I understand you likely can't address such as cable too short, connnectivity, flickering etc etc. Was hoping someone could address whether Apple takes these observations on board when producing the next version of an item