One of the biggest features of Born of the Gods and Journey into Nyx that we know of so far is the two-color minor god cycle, of which each set will get five members. I have written extensively about the speculation surrounding them thus far, and though we know the character identities of all ten remaining gods, there's very little else we do know, including to what degree they'll function like the Theros Five.
However, on his Tumblr blog, Mark Rosewater has clarified a couple of points about the minor gods. First, when soliasildo asked, "Are minor gods going to be Mythic rare, or just rare? Because they're minor are they going to be indestructible like the big five?" he answered:
They’re mythic rare. As to how they’re going to work, you’re going have to wait on that until we reveal the first minor god.
Of course, "minor gods" isn't a statement of how powerful they are - it just means they have a smaller divine area of influence, being gods mostly of social ideas rather than inexorable natural forces. So it's likely that they'll be indestructible, and almost certain they'll be devotion-powered - but that's where the similarities may well end.
One thing that was associated with the major gods in Theros was their rare legendary artifacts - not so with the minor gods, sadly. When brian3366 asked, "Will the minor gods have weapons also?" Rosewater said:
No, they will not. Only the major gods have weapons.
He later clarified they were cut for space, given the limitations of small expansions. It's a pity, but there's always custom design for those!