Wheel of Fortune weekly themes....

I can answer a lot of these questions from after Season 14, when I was watching regularly (and some from Season 11, when I first saw the show):



Yes, this is the first time since at the latest 1991 (Season 9) that there's no holiday themed week on the week that spans Christmas Day or the last weekday (or new episode) before. Ever since 1996 (Season 14), it was Happy Holidays week the week of the Monday after December 18. Up until Season 14 (and starting at the latest, Season 10), that week was Family Week, and in Season 14, that was December 16 - 20, 1996, just before Happy Holidays December 23 - 27. In Seasons 10 - 13, it was the week of the Monday after December 16, since the week of the Monday after December 23, up until Season 15, was the rerun week.



They had Sweethearts Week in 1996, 1997, 2002, 2003, 2004, 2005, 2006, 2009, 2010, 2011, and again this year (Seasons 13, 14, 19, 20, 21, 22, 23, 26, 27, 28, and 29).



They never had an Easter themed week, at least since Season 11.



Of course they never had a 4th of July week, since that's always during the reruns. However, in 2010, I'm sure airing the Historic Boston rerun June 28 - July 2 was intentional.



Since Season 15 (1997), the only seasons with no Halloween week were Seasons 23 - 25 (2005 - 2007).



They never had a Thanksgiving themed week, at least since Season 11

Also, for New Year's (the first new week of the year), they had Wheel Into all years from 1993 - 1999 (Seasons 10 - 16). After that, last season they had a New Year's themed week from Vegas December 27 - 31, 2010, but they called that one New Year's Week, not Wheel Into 2011. There was no New Year's themed week at all called Wheel Into 2000 - 2010 (or otherwise, Seasons 17 - 27), and there isn't this year.

I also think that in Season 15, airing British Isles March 16 - 20, 1998 was intentional for St. Patrick's Day. But interestingly enough in Season 17, they aired that one week too late for that, as it was March 20 - 24, 2000, and in Season 16, it was at a whole other time of year, October 5 - 9, 1998.

And let me also add Spring Break in 1997, 1998, 1999, 2001, 2002 (when it was called Spring Fling), 2006, 2007, and 2011 (also called Spring Fling, from Vegas) (Seasons 14, 15, 16, 18, 19, 23, 24, and 28).

And let me also add Endless Summer either in June ending the season or in September starting the season. This was in 1997 and 1998 (the last weeks of Seasons 14 and 15, respectively, and let me also add that the week before the latter was Summer in the City), 1999 and 2000 (the former the first week of Season 17, the latter the second of Season 18), and 2008 (first week of Season 26).

For winter they've also had: Winter Wonderland (1996, Season 14, Thanksgiving week, December 2004, Season 21, and maybe also count Sony Winner Wonderland in December 2005, Season 23), Winter Getaways (January 2004, Season 21), and Winter Holiday, January 2008 and 2010 (Seasons 25 and 27, respectively)

For fall, we have Fall Foliage in October 2009 (Season 27). But as for other fall themed weeks: Inns of New England in 1997, 2000, and 2006 (Seasons 15, 18, and 24, though the latter was in December, and the Season 18 had something not theme related as a prize, the Charlie's Angels boat since that was the week that movie came out), Great Getaways in September 1998 and 1999 (Seasons 16 and 17), and this season's Bed & Breakfast in October 2011.

And maybe I should also add in Season 14, Discovering the Americas October 7 - 11, 1996 (week before Columbus Day).

I can let you know more if I remember them, as this is all from memory. In the meantime, I hope all this info helps!