A PRO processor is intended for operation within a managed computing network, as for a business. It can also limit it's suitability somewhat for typical home and school useage since security is it's primary concern.
I suspect by "2 channel" it means dual channel memory which is the same as any other laptop or desktop processor.
10 deg higher temp for the 5850u: higher max operating temp or Tjmax. A somewhat cynical guess says AMD doesn't figure these things will be operated by a business longer than a typical 3-5year replacement cycle and this reduces maintenance for their IT staff to clean dust out of clogged cooling vents. You (as a private owner) don't want to be operating at that. They both have a 15W TDP, that will govern performance potential in a laptop more than anything else.