Hi Hobie,
No, the A350 is an updated version of the A330 (the A350-800 an updated version of the A330-200 and the A350-900 of the A333) and is certainly aimed at the market being targeted by the 7E7.
To my knowledge, the Boeing aircraft is still the 7E7; a Boeing spokesperson said there are divided opinions on whether to rename it.
Also, looking at an Airbus ad in this week's Flight (inside front cover), one of the routes shown for the A350 is DUB-SIN. Aer Lingus is certainly in Airbus's sights and of course, being an existing A330 (and A320 operator), you have to say it has a lead there. However, the 7E7 is a very impressive aircraft. To my mind, the biggest chance for Boeing getting a shot at EI could be in the first half of next year. If a new deal is agreed to allow EI more US access (i.e. amending the SNN stopover to allow more n/s from DUB), it will be a lot easier for Boeing to provide aircraft; there are very few Airbus widebodies now available (no A330s), but a few 777s are available. If Boeing could persuade EI to lease these to add capacity and replace A333s as their leases run out and offer a good lease deal as part of a 7E7-9 package, they might have a chance.
Note also that the A350 price tag is considerably higher than the 7E7, it's available well after Aer Lingus wants a new type (although no doubt a bridging lease could be organised) and the 7E7's fuselage cross section will allow a 9 abreast layout (although intended for 8 abreast); the Airbus won't.