Coming up today (14 May at 5:15 p.m. EDT/23:15 CEST), NASA will conduct a mission briefing. You can watch on NASA TV. Astronauts completed the first EVA (spacewalk) in seven hours and twenty minutes, replacing WFPC2 with WFC3 and upgrading Hubble’s computer, the Science Instrument Command and Data Handling Unit.
Meanwhile, the ESA HST team reports that there was about 2 degrees of solar array slippage during the full EVA day. This is normal and the movement is completely within expected parameters.