The following information has been released publicly by VZW advanced support so I feel I can share this now:
If you want to use the UML290 on the Mac/Linux/UNIX/other-platforms you can now do so if you have the engineering knowledge or a little know-how:
Quick Notes: Verizon 4G LTE uses the GSM APN authentication method through a GGSN (similar to AT&T) and 3G (1X/EVDO) traditional uses the HA CDMA method. The old CDMA authentication method has been posted years before so I won't repost that.
You WILL NOT GET SUPPORT UNTIL THE OFFICIAL VZACCESS Software comes out on the Mac.
So on the Mac connection manager (generic apple), make a profile for your UML290 hardware, should be a modem. Make a GSM connection profile with the above. Phone number is your data-stick phone number (fake phone number, used for system identification, get it from VZAccess or your account page online). Account name is "firstname.lastname@example.org". (Basically add @vzw4g.com to your phonenumber. Password is "vzw", same as 3g CDMA. In GSM/3G/4G carrier use generic (no special parameters). Model is GPRS (GSM/3G, same as 4G). GSM APN is "vzwinternet". CID is 1 if your drivers need it.
Enjoy 4G LTE GSM technology by VZW on your Mac! I will be running this on my Linux engineering dev machine soon.
If you upgrade your device online then I believe they'll ship you a phone with new SIM -- you need to finish the activation process once you get the order and then the new SIM will start working and...