There's a bumpup of around £30 to go for the latter (which Amazon tells me is the newest version). I also noticed it has a slightly lower GHz (1.6 rather than 1.66). Reckon it's worth dishing out the extra £30 or not?
I have just re-ordered the updated version after spotting that there was a newer version (thankfully it had not yet shipped).
After looking around for reviews of the N570 and N2600 there seems to be very little difference in overall performance. However the consistent difference highlighted seems to be that the N2600 uses less battery (whilst producing less heat) and has far better graphics capability allowing 720p viewing on iPlayer and YouTube etc. which was more or less impossible with the N570.
The cost difference to me was only £13 so thought it would be worth it.
Also just to point out that almost every review of the NC110 has been good but the advice has been that it's best to upgrade to 2G RAM asap!