Nothing about cloak detection was nerfed in beta, Science ships were the best tanks and DPSers in open beta this meant no one was playing Cruisers or Escorts. They nerfed the hull and shield strength of Fed Science ships (note that most Klingon ships are still lower in hull and shields than Science ships). This made the Cruiser the dominant class for Feds as it was the tank and can DPS better than an Escort. What they failed to do was revisit the nerft to cannons that has kept the Escort as the step-child of the Federation since mid-open beta.
Charged Particle Burst is a great ability to detect cloak, try it.
Science ships were never good DPS'ers. Most ran Science and Escort in OB. Now it is mostly Cruiser and Escort. Regardless of the situation, one ship class seems to be left out and that is a problem.