You can find any number of rumours about supposed face lifts, along with dates for the Mark 8, as I'm sure you know. Distilling all the stuff I've seen, the best bet for me is that the Mark 8 is due to be revealed late this year, so deliveries this time next year. Autocar suggests that there will be what they call "mild hybrids" across the range. I reckon, given such a big change, that the new models will come into the market in stages, as they sometimes have in the past, with the big selling varients coming first and the top end cars, like the GTi, later.
Like you, I wouldn't get an early car anyway. Much better to let others sort the teething problems!