I just received mine today and probably several other people will be in the next few days as well. Some initial concerns/observations that may throw some people off that are used to v1.
First off, the presses are time based. where in v1 you held it down until it started printing out the characters, with v2 you hold and then let go after 1 second (0.3 - 1.5 technically) for first config and 4 (2.5 - 5 technically) for second config. If you hold it down nothing will happen and could later on actually reprogram the key if you hold it down too long. This didn't get me at first but switching between v2 and v1 I keep getting it confused.
There is no second config when you receive it from the factory. What that means is you can hold down the button anywhere in the .3 - 5 second range and it will emit the first and only config, which is setup with OTP with yubico
The OTP id itself was interesting to me as well. It appears the v2 id's are sequential and padded with c's. for example my id is ccccccccXXXX where the X's are different. Was kinda startling since the v1 was apparently random but there's no reason to be security concious about it. Remember the strength is no one aside from the authentication server (yubico in this case) can decrypt the stuff after your id.
Some links of interest
Hope this is all useful to others