That's pure speculation on the part of disgruntled fans.
no, actual articles. Bethesda has said they are working on a fix but don't know when or if it will actually happen. Skyrim was built for the 360 which has its memory better allocated than the PS3 despite PS3 having more total memory.
article stating that dawnguard may never be released for ps3: Invalid Link Removed
article stating that hearthfire is making it even harder to find a solution for the ps3 problems: http://www.cinemablend.com/games/Skyrim-Dawnguard-DLC-Still-Working-PS3-46382.html
they're still working on it and that makes me feel a little better, but it doesn't look good when they never even managed to fix the initial issues on the ps3