This is AWESOME.
By the way, I wasn't intending to NOT use travel pass, I get it's benefits. But with Travelpass *AND* Google Voice, you can call anywhere in the world with the Google Voice rates. Whilst travel pass calling minutes are great for calling the USA or country to country, combined with Google Voice, you can call country to another country at Google Voice's great low rates.
So, using Travelpass on it's own, I'm in France right now, calling the UK would cost me $1.49/minute. If I use Google voice, it's 0.03c
If I call Australia using Google Voice it's about 0.07c 
The other advantage is that with Google Voice, they see my Google Voice number calling them, as opposed the Verizon number (which I don't use in the USA as I use my Googe Voice number all the time).
This is great news.