This is a bit cryptic.
Mike O'Day, Our Texas House Rep, who won last year's special election to replace Glenda Dawson, will not return to office next year, but it is debatable whether he is resigning or simply not running again. (try make sense of the following stories here and here). Mostly the blogs just post links to each other.
Another question is why? One report points to his health, he had a heart attack early in the session. Another is related to an odd note in Paul Burka's Blog (Texas Monthly) regarding "ungentlemanly behavior."
The rumors are flying, but nothing is substantive.