I had the same concerns so i researched it a bit more. While the processors used in these new macbook pros can address up to 32gb of RAM on the system, the DDR3 standard accomodates for up to 8gb per chip. With 2 chip slots, you are already maxed out, regardless of whether the chips are soldered on or not, so it makes no difference.

Yes, it's soldered on, that's part of the reason they can make it so thin.

The point in buying it over the air remains: 15", retina, etc.

This is not something to be mad about. If you buy the maxed out 16GB, well, it's maxed out anyway.

If you buy the 8Gb, it's a compromise you make. You'll live with the 8GB, or sell the laptop to upgrade. It's worth the trade-off (small size, etc.)