Out of curiosity I was just looking over the history of snapshots-to-official-release dates, and it may be a while before we see 1.7 officially launched.
1.4 - first snapshot release: 09 August / official release: 25 October
1.5 - first snapshot release: 03 January / official release: 13 March
1.6 - first snapshot release: 18 April / official release: 01 July
1.7 - first snapshot release: 05 September
That's around two and a half months on average between first snapshot and official release! By that logic we won't be jumping into 1.7 until mid-November.
I guess what I'm saying is, no need to put off building anything in the current world.
I'm going to continue along with the pieces for the park, and then hopefully find a spot at new spawn to have them transported to.