I predict that the end of this season will see Joe dying instead of Iris. This will cause some sort of temporary rift between Barry and Iris. But, the newspaper article will change back so Barry doesn't lose hope.
Then in Season 4 we'll see Iris becoming a capable reporter who gets assists from Wally. Barry, and Iris will make up eventually, of course. I think Frost will become a recurring villain in season 4 with Draco devoting most of his time to her rehabilitation. This will leave Barry, Cisco, Earth 2 Wells, and sexy Quick to work on the other villain of the week cases. Hopefully beatnik Wells gets raped by Gorilla Grodd, and dies in the next episode.
But, I see him making a Heel turn during the Finale. As long as they do away with him I don't care.
Also, I see Eobard Thawne undoing the death of Eddie somehow on Legends. Perhaps a resurrected Eddie will become the new (Or first?) Reverse Flash.
Next season's Villain will be Johnny Quick of the Crime Syndicate. Since Jay Garrick is Earth 3 Flash on the show I guess Johnny Quick will have to be from Earth 4 or something. Hopefully Bart Allen, and Max Mercury will appear at some point.
Maybe the next version of Wells will be Max Mercury from another Earth. A veteran speedster who mentors Wally, (during the temporary Allen-West rift) and eventually Bart.