HAJ could prove quite a sweetspot for a carrier like BE. Many routes from HAJ to MAD, AGP, BUD, ARN, WAW, PRG, NCE, VCE, FCO, DUB, LIS have been flown in the past, and generated pax, but never quite enough for the now standard A320/B737. A few of those sectors may be more suitable for an Embraer rather than the Dash, but there is no competition from FR and EZY as stated above, and Germanwings is weak at HAJ.
Also BE just entered a codeshare with AB of course... so HAJ-VIE and HAJ-STR could also be taken on... and CDG for AF?! FKB or BSL could also be an interesting option. Then there are the LH monopolies to MUC and LX to ZRH...
Oddly enough, the only destination that never came to my mind would have been the already introduced LYS...