Looking at a decreasing backlog, Embraer is trying to decide about whether or not to reengine the E-Jets family. They are in talks with GE, PW and RR. I think that it's the first time that Embraer mentions that improvement in fuel burn over the current CF-34 would be an estimated 12-15%.
http://www.flightglobal.com/articles/20 ... -burn.html
Reengined E175's and E190's would be excellent contenders for the RJ replacement of SN.
By my estimations, Embraer could get a reengined E-Jet family ready by 2014, at the same time as MRJ's if the MRJ's are not delayed.
If I had to choose between reengined E-Jets or MRJ, the choice would be very tough. The E-Jet is heavier, has more drag and will still burn 5% more fuel than an MRJ. It also has known but not rectifiable design philosophy issues, high parts price and software/publications issues.
On the other hand it has a proven track record and an excellent safety record that the MRJ does not yet have.
If reengined with PW1000, they would share technological commonality with an eventual CSeries fleet.
Combined with the profitable African network, the acquisition of these new generation RJ's to replace the thirsty and costly Avro RJ's will make of SN a stable and profitable airline.