As of June 1, 2017, there is a Power BI licensing change coming…
The quick summary is that Power BI free is going to gain the ability to automate refresh via a personal gateway, but will lose the ability to share dashboards. It's moving more to a "personal" experience. The new licensing model is essentially changing the free vs paid barrier from automating refresh to sharing.
Microsoft is extending the Power BI Pro trial out to a year, which is great. So if you do share pro content, your audience will be able to say "try pro" for up to a year before they need to buy in to a pro license.
In addition, there is going to be a new Power BI Premium feature that allows much better scalability for large companies.
I'd go into more details on this, but to be honest, my friend Matt Allington has done a fabulous job of summarizing the changes (both good and bad) on his site (and article that is well worth the read.) You can find that article here: http://exceleratorbi.com.au/power-bi-licences-changes-good-bad/