Not likely any time soon. Most of the national channels that have gone HD have much higher viewership numbers overall. I wouldn't expect HD from either of them for at least a couple more years. If anything, I imagine they will probably just have HD subchannels during game time, and then just rebroadcast the raw HD feeds from the feed providers. (like setanta does with the raw SD feed for setanta xtra)
http://www.epltalk.com/hd-coming-to-fox-soccer-channel/3924 http://www.multichannel.com/article/CA6620568.html?industryid=47194