On ING, I think they're going beyond flirting and want to open open up their systems & data to 3rd parties, although probably selectively.
In this interview (Dutch), ING CEO Ralph Hamers states a couple of interesting things which indicates they believe in open banking data: "If a consumer wants to use other banking products within ING Bank's platform, then that shouldn't be a problem". More in English (including video from Money 20/20) here. ING has a stake in Kabbage which they use for their SME lending in Spain (Santander is working with Kabbage in UK). He states he's actually looking forward towards the introduction of PSD2 as that will be positive for the consumer.
At the recent Dutch Blockchain Conference, ING gave some insights on what's going on within the R3 consortium and they highlighted the importance of open source initiatives such as the Hyperledger project. Although they admitted most of the time spent in R3 so far was around figuring out what exactly the Blockchain is and what it can do, and not many tangible experiements yet.
Furthermore, they run several FinTech accelerator programs and partner with c. 50 FinTechs now. I cannot imagine that must solely be for ING's internal gain, the FinTechs must be getting something out of it as well, e.g. access to ING's huge swaths of data.