Using Skype with location setting enabled, I noticed the constantly blinking dish icon just some weeks ago. So I'd rather doubt that probs are caused by Googles PKI. Last root certificate changes for supl.google.com were in mid 2011 (from Thawte to Equifax/Geotrust).

As supl.google.com has stopped working with N900 I started searching for other supl servers, unfortunatly there are not many around. I found

supl.vodafone.com
supl.sonyericsson.com
sls1.sirf.com

seemingly to be active. With supl.vodafone.com my dish icon stopped blinking after some minutes, so I'm fine with this. Didn't check the others for location data, just for propper TLS responses .