I think it's important to understand the differences between the various versions.
1) The first cloud offering was DW CS6 (ver 12). It received several updates.
2) Last year DW CC (ver 13) came out. It too received several updates.
3) This month Adobe launched a new version called CC2014 (ver 14). It will no doubt receive updates throughout the year.
AFAIK, subscribers can have all 3 versions installed along side each other if desired.
Creative Suite's upgrade cycle was 18-24 months. Creative Cloud appears to be rolling out new versions every 12 months.
Nancy O.