Hmmm do I cancel and wait for sz77 .....
I would. Reason?? Firstly the Z68 based version will drop in price and secondly I would rather get the Z77 for the same price as the Z68.
Also,Haswell will be the next socket change next year,so the SZ77R5 will be the top model together with the SX79R5 for the better part of a year.
The only reason this is happening is that it took yonks for Shuttle to get the SZ68R5 released. It should have been out a very long time ago and not in 2012. This is why the SZ77R5 is arriving so near to the SZ68R5!!
I'm also going to keep the pressure on Shuttle to supply motherboard upgrades at a reasonable price. So it maybe that you will be able to upgrade the Z68 motherboard to a Z77 in the near future without needing to buy a new case, PSU and heatsink.
The better option would be to just get the SZ77R5.
BTW,the site which advertised the SZ77R5 is NCIX which is one of the biggest computer parts retailers in Canada.
Even Crucial is starting to list compatible memory on their website. The SZ77R5 is being released soon it seems.
Waiting a few weeks makes more sense than wasting money down the line on a new motherboard.