this product is way overdue. i have always felt that tree climbing should require absolutely no physical exertion. i think we will find that this is the future of tree climbing.
i have been working on a similar product myself. the prototype is nearly complete.
http://store.baileys-online.com/cgi-bin/baileys/886?mv_session_id=Mub8zaVP&product_sku=49470
using this product from baileys, which is basically a winch attached to the powerhead of my chainsaw, i tie in to the handlebar on my chainsaw and run my rope through the winch. then i just fire up the saw and hold the trigger and i fly up the tree. once at the top, i put the bar back on and top the tree and massacre the rest on the way back down.