Saw this article on the Guardian website,seems there could be some more baggage handling strikes on the way:
http://business.guardian.co.uk/story/0,,2119066,00.html?gusrc=rss&feed=networkfront#article_continue
They'll be more delays at HEathrow with the protesters camping out for a week:
http://charlieharvey.org.uk/dbpage.pl?id=47
And good old Gordon says that due to the terrorism threat there could be substantial passenger delays:
http://news.bbc.co.uk/1/hi/uk_politics/6276264.stm
Remember to take a good book with you for your holidays, you may need it while you wait for your flight