In a very surprising move, Visa has just shut down all Visa cards issued by WaveCrest, which is the card issuer for almost all of the current Bitcoin Visa cards on the market, including Xapo, Bitwala, TenX, Wirex and Cryptopay (which I'm using). Monaco is as far as I have read (so I cannot personally confirm it) the only card that works right now, since they did not use WaveCrest and instead work directly with Visa.
Update: As 
Dr. Julian Hosp from TenX has said in this video that they were told only 12 hours before the cards where shut down. If you believe the people on Twitter, there are now some people who cannot buy food thanks to Visa's unannounced shutdown with zero grace period.
At the moment it looks like Bitcoin card dealers will try to switch to other card issuers, so new Bitcoin cards should be available from them at some point, but that could take a while.
I don't know exactly who is at fault here, Visa or WaveCrest, this should become more clear as more information about this comes out.
You can find more discussion and information about this on Hacker News and r/Bitcoin