Unreal Engine is going to be free but as the clever guys who writes things way more complex than it really is says:
"It's free with a 5% royalty on gross product revenue after the first $3,000 per game per calendar quarter from commercial products"
So yeah, free.
And if you're lucky enough to earn $3.000 from a game, I bet you're happy to share a few amount of money with Unreal - It's the same thing as before, except the Engine itself is free now!
Also they have just released this amazing update, just makes everything a whole lot better.
Unity 5 is also going to be free .... but
All of the features is in Unity 5, however there are some limitations about that you can't customize the splash screen unless you pay for a pro license. They've introduced this "Personal" license, which suits personal projects, and you can actually distribute your game to a limited amount of platforms without paying - I'm not really sure about how this system works, but I'm somehow sure that there will be some kind of payment to Unity in the personal license.
When that's said, they have 21 platforms... wait, what? Yeah! 21 platforms that you can export to.
Yesterday I watched the Unity 5 livestream, where they showed some sample projects from Unity 5.
The visuals are (in my opinion) not as great as those you can achieve in Unreal Engine, and I definitly think that Unreal has the real bonus in the visuals, however, Unity 5 is easy to use, and is very use-friendly.
Don't love my English ^^