Updated October 12
Update with my limited knowledge of Republican Primaries effecting Williamson County.
(Just for the record: I am not making any endorsements.)
Texas Senate, District 5: With Steve Ogden's retirement, Representative Charles Schwertner announced his candidacy, and most pundits consider him a shoe-in. There have been some rumors about a possible Bryan/College station candidate, but no announements as of yet.
Texas House District 20: Since Dr. Schwertner seems to be heading to the State Senate, SBOE member Marsha Farney and former TC Republican Party Vice-Chair Jeff Fleece have announced candidacy for HD20. Two other possibilities, Jeff Stockton of Georgetown and Burnet County GOP Chair Linda Rogers have indicated they will not run.
Texas House District 149: After the overwhelming community support shown for Republican Tony Dale, all other candidates have bowed out. Representative Larry Gonzales of HD 52 remains very popular and is unlikely to draw a GOP opponent.
State Board of Education, District 10. With Marsha Farney jumping to the Texas House District 20 race, former SBOE 10 candidate Rebecca Osborne has announced another run.
Justice, Third Court of Appeals: Scott Field has announced he will tackle Democrat Diane Henson for Place 3. Amen to that. Madeleine Connor has filed a treasurer form with the State; Connor ran for District Judge as a Democrat in 2008, but lost in the Primary. In 2010 she ran as a Republican for Justice of the Peace and also lost in the Primary.
425th District Court Judge: Incumbent Republican Mark Silverstone will be challenged by local family law attorney Betsy Lambeth. for the GOP nomination.
Williamson County Attorney: Attorneys Hal Hawes and Rick Kennon have both filed to run against beleagured incumbent Jana Duty.
Williamson County Commissioner, Precinct 3: Incumbent Val Covey will be challenged by sometimes Republican Greg Windham, who ran against Covey as a Democrat in 2008 and briefly served as the Williamson County Democrat Party Chair in 2010.
Supreme Court Justice, Place 2. Steven Wayne Smith has filed a treasurer form to run against Republican Don Willett. Smith lost in 1998, won in 2002, and lost again in 2004. Smith previously challenged Willett in 2006.
All of the known candidates for the Republican Primaries are listed at the Williamson County Republican Party website.