This year may present a unique opportunity. Long term capital gains tax rate is 0% for those in the 15% bracket and lower during 2009 and 2010. So it may actually be beneficial to take some tax gains now. Significant state taxes may counteract or kill any potential benefit since the LTCG's will still incur state income tax liability (at least in my jurisdiction).
Caveat - I haven't actually ran the numbers, but it seems like a "free lunch" up to the point you exhaust your 15% bracket. Not sure how losing all those tax losses comes into the equation since those can offset ordinary income at a rate of $3000 a year. So do your own due diligence.
Retired in 2013 at age 33. Keeping busy reading, blogging, relaxing, gaming, and enjoying the outdoors with my wife and 3 kids (4, 10, and 11).