Great thread. Thanks.
One blog site I write for with new releases in the Ambient community is Fluid Radio:
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It averages three new articles per day, has a dedicated 24 hour two channel web stream, an online store to pick up vinyl and tapes if that's your sort of thing. In addition to this a MixCloud hosting of artists in the scene (including the bloggers aboombong noted), track giveaways in the "Underexposed" section, and a forum for scoping more content.
Drop 'Mick Buckingham' into their search if you want to read some of my reviews.