.... the cast of "The Flash" were on hand to discuss the show and Tom Cavanagh confirmed that he is indeed Reverse-Flash as suggested in the final minutes of the mid-season finale. Some confusion arose as to whether he was the character, or Dr. Wells had found/was building the suit which someone else was using.

the 17th episode, which will feature a look back
at the night Barry’s mother was killed.
“We’re going to see what happened that night from the Reverse Flash’s point of view,”
Kreisberg said. “I didn’t say it was from Wells’ point of view,
I said it was from the Reverse Flash’s point of view.”

So, does that mean there’s another Reverse Flash out there?
Many people suspected that Eddie Thawne (Rick Cosnett) was the man in the yellow suit,
given his name’s similarity to the Reverse Flash’s alter-ego in the comics.

“His name is not an accident,” Kreisberg said. “Eddie’s connection to the Reverse Flash lore
is going to pay off big time in the back half of the year.”

It’s interesting to note, however, that Cavanagh said,
“There is just one Reverse Flash.” That should raise some crazy theories,
including whether Harrison is an older version of Eddie.
“When we get into that moment and really start parsing
through details of what that moment is, it’s going to be very
gratifying to the audience. It’s got deeper levels. There’s so much more to it.”

Since time travel is somehow involved, could Barry travel back to that night and end up killing his own mother? I know it's Batman-level darkness there, but his life would have been radically different and most likely he would have not become the Flash at all without this event putting him in a certain place at a certain time.

They said she was stabbed through the heart, so I don't think he could do that accidentally.