Welcome to Flyertalk. Membership Rewards points can be transferred to Delta Airlines. Here is Delta's award chart for upgrades:

http://www.delta.com/skymiles/use_mi...ards/index.jsp

Look at the section headed: Between the 50 U.S., Bermuda, Canada, the Caribbean, or Mexico AND Japan, China, or Korea via the Pacific The catch is in the fine print, upgrades only apply to "select fares". I suggest you speak with Delta to compare their lowest available fare to the lowest fare which is upgrade eligible to understand the real cost of the upgrade.

Membership Rewards points cannot be transferred to Korean Air.

Intercontinental Hotel Group (Crowne Plaza) and Marriott no longer participate in Membership Rewards. See this link for a full list of transfer partners:

http://www.membershiprewards.com/cat...readcrumb=true