Very much doubt it will have usable USB audio out of the box (it'll have Jelly Bean USB audio, but that is basically useless since it only works with devices made specifically to interoperate with it and will NOT work with any existing USB DACs).
What I have seen of the display doesn't sway me particularly. The resolution and density are impressive, however it won't look any sharper than lots of present displays which already exceed the limits of human visual acuity, so from a PPI point of view the gains are largely irrelevant. Because of the very small pixels the display seems to lack in the brightness department compared to other current displays, which will make for worse sunlight visibility too. Finally, the colour balance is very titled towards blue, so it has lost the benefits of colour reproduction accuracy that LCD/IPS displays usually benefit from in comparison to AMOLED. If you see it side by side with other displays these defects are very obvious (can't remember who had a picture of it with i5/One X/S3 etc, but the differences weren't particularly subtle).
All of which is not to say it may not be a very fine phone, only that the OMG 1080p! screen isn't a completely unalloyed good, and I don't think it should be an overriding influence in decision making in terms of this phone Vs others.
Oh, and should mention that Paul Obrien from Modaco says the international one will have a micro SD slot.