Wrong about the CS100s. I have no affiliation with Bombardier or UAL, but I need to offer some corrections. First, the order in question is for 40 CS300s - these aircraft are bigger than the CS100 by 20-35 seats depending upon the configuration. Republic originally ordered them for Frontier to replace Airbuses. And by the way, this airplane is super-advanced with very fuel efficient engines (GTF), FBW, side sticks and Collins ProLine Fusion cockpit (like what you find in high-end Global Express biz jets - it makes the 787 cockpit look old) with HUD - it puts the E190/95 to shame. Here's a cockpit photo from the smaller CS100 that SWISS will operate:
http://www.airliners.net/photo/Swiss-International-Air/Bombardier-CSeries-CS100/2733574/L/&sid=446b3e519dff7190005e8a44dde5b675

Meanwhile Air Canada can't wait to dump their E190s and traded them off to Boeing when they ordered the 737MAX. So, if they aren't good enough for Air Canada, why should UAL want them? I am not saying the E190 is terrible aircraft - it just can't compare to the CS300 in terms of performance and innovation.

The CS300 can also fly from Ft. Meyers to Seattle full in the summer (big overhead bins for the pax) or to Hawaii from smaller California airports and will soon be certified to land at London City Airport (steep approach and short runway). This isn't a dilapidated/worn A319 or 737-700. Recall that the C-Series program was largely delayed due to an engine fire - it wasn't Bombardier's fault but it suffered a big cash loss due to the resulting 6-month delay.

This airplane, compared objectively with the E195, A319 and the 737-700 is a GAME CHANGER. This is not a Q400 with jets or a junky stretched CRJ. Th program needs some serious momentum from bigger orders and UAL potentially taking Republic's order for 40 CS300s would be very helpful to the program.