being push one month early is better than being push 7 or 8 months period (Mass Effect 3).
in the Captivate event, they also showcased full one mission for Leon's story - almost everything from the character fluid movement, the health bar, ammo, etc.
so I'd say, everything is already finish up except for a few tweaks - credits, menu, subtitles, aligned the cutscenes, etc. also they still working on to convert it properly for PC gamers - improve graphics, buttons configuration, 3D vision, etc.
even the day 1 DLC is just for the mercenaries maps. exclusive 3 maps actually.
I guess it's better than how EA push BioWare to release Mass Effect 3 early (original date should be around October to November but we got it on March), it rushes everything and the ending were not properly done (but at least we get the Extended Cut DLC for FREE).