Drows in Eberron are different. They don't need to hide in darkness, they were slaves to giants for thousand+ of years. When giants died (well, most of them), so did their imperium. Then Drows elves from Eberron were already used to live under sunlight, and many years later men and other races came to the continent we talk about - Xen'Drik.

This is the place where DDO (most of it) is placed to date. Continent of Xen'Drik isn't the main continent of Eberron, it's a new-found one, one still to be conquered. Races who came there either fight dark elves, or are friends with them - dark elves (drow) are far from being united...
Most dark elves don't know much about their origings, thousad years of slavery did them much hurt. But this race hides dark secrets, and is one of the oldest races of Eberron. It is possible that there are some places on Xen'Drik, where drow could learn about their lost power and glory.

Either way, sunlight isn't a problem for them, although they prefer dusk (feel more comfortable with it) and see very well in complete darkness.