I was initially undecided about buying an iPhone X, so I chose not to wake up at some ungodly hour to place a preorder. If and when I decided I wanted one, I was willing to wait several weeks until shipping times became more favorable and stock more plentiful.
I happened to check the Apple Store app earlier today and, while delivery times for all models were showing as 3-4 weeks, some models were available for same-day pickup at my local Apple Store (World Trade Center). I was able to buy and collect exact model I wanted (256GB Silver) this morning, the day after launch1. My wife even placed an order a couple hours later for a different model (256GB Black) and was still able to collect it this afternoon.
This isn't an isolated experience and I've heard about Apple Stores in different parts of the country all having decent stock levels. At the store I collected my phone from, I overheard a member of staff say that they had received so many iPhones for launch day that they didn't even sell them all—today's stock is mostly leftovers.
If you didn't preorder the iPhone X but want to get one soon, try your local Apple Store using the Apple Store app. It seems Apple is making a huge effort to keep stores well-stocked.
Some people I know who did wake up to place a preorder still haven't received their phones. ↩