The Democrats will get a relative wave in this election, but it won't be enough to take control of the Senate. The map was too tough for the Democrats to do that anyway. They're playing defense in 26/35 Senate races.
Historically, a "wave election" generally correlates to a 7-9% popular vote victory across the nation's races, and I think the Democrats will likely get something like that. The problem is the map is so advantageous for Republicans, that Democrats probably need to win the popular vote nationally by 10-11% to have a shot to take the Senate.
I expect a 51-49 or 52-48 Senate edge for Republicans. I think we are looking at a Democratic House and Republican Senate, which I think constitutes a so-so day for both parties. The Democrats get a piece of control, but the Republicans retain the more powerful chamber.