SurferTim:
@Jack: Let me know how it does for you. If good, then we only have one more to go. The ENC28J60.
@Tim, for a week or more now, I've been running a Cosm test sketch which posts six data points to each of five data feeds once per minute, with five seconds between posts, using a WIZ820io. The new library code seems to work as well as before. This is not to say without issues, but I suspect these are due to a combination of network or web site delays and perhaps my code 
Probably not perfectly definitive results, but I hope it helps.