This may be weird, but have you guys switched to the SIM cards included in the box? The first week I had mine, it used to get really hot, I read somewhere that switching to the new sim card fixed that. Just a guess really, mine gets warm, but only after intensive use for about an hour or so..
HTC Dream (G1) (sold), HTC Leo (HD2) (sold), HTC HD7 (Zune player), Motorola Defy (Sold), Viewsonic G-Tab (Broken
Current HTC Amaze 4G Revolutionized NonSense (waiting for a CM9 or AOSP build of some sort)
Google Nexus 7 (Please ship soon)