Has this been confirmed?
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Not sure that it's BTO only. On the MBA product page it says that all MBAs can accept 4GB RAM.
Yep, quite a number of review sites have confirmed that you can't add it later. Oh well, at least this time it's reasonably priced; I ordered a 13"/128GB/4GB machine last night.That only means it's supported, not that it's upgradable after purchase. If you look at the tech specs page under Memory it says "onboard." That is tech jargon for soldered on to the logic board. RAM is only BTO. It's now or never.