Someone asked in another forum if the 1TB Hub and Live Streaming models were being discontinued because they are out of stock many places, so I researched a bit and found the answer at J&R. There are two new models of Hub coming soon, (perhaps the 1TB is discontinued) and the Live Streaming, although out of stock, appears to hang around a while longer. See this link for details:
http://www.jr.com/product/productListing.jsp?Ntt=wd+tv
Edit: the above site is under maintenance right now, so I checked another big NYC retailer – B&H, and have more info. They already have the 2TB in stock and the 500GB model is due in mid-April. Se this link:
http://www.bhphotovideo.com/c/search?Ntt=wdtv&N=0&InitialSearch=yes&sts=ma&Top+Nav-Search=
I honestly don’t see any other upgrades to the units other than the drive size. Hub owners might know what else is changing.