Here's my log, on deployment. We've noticed this problem around 7am, GMT, Nov. 27th.
.......
05:05 PM Cloning 550 static files.
05:05 PM Cloning 1118 application files.
05:05 PM Uploading 9 files and blobs.
05:06 PM Uploaded 9 files and blobs
05:06 PM Compilation starting.
05:11 PM Error 500: --- begin server output ---
<html><head>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<title>500 Server Error</title>
</head>
<body text=#000000 bgcolor=#ffffff>
<h1>Error: Server Error</h1>
<h2>The server encountered an error and could not complete your request.<p>If the problem persists, please <A HREF="
https://code.google.com/appengine/community.html">report</A> your problem and mention this error message and the query that caused it.</h2>
<h2></h2>
</body></html>
--- end server output ---
Precompilation failed. Your app can still serve but may have reduced startup performance. You can retry the update later to retry the precompilation step.
05:11 PM Starting deployment.
05:11 PM Checking if deployment succeeded.
05:11 PM Will check again in 1 seconds.
05:11 PM Checking if deployment succeeded.
05:11 PM Will check again in 2 seconds.
05:11 PM Checking if deployment succeeded.
05:11 PM Will check again in 4 seconds.
05:11 PM Checking if deployment succeeded.
05:11 PM Will check again in 8 seconds.
05:12 PM Checking if deployment succeeded.
05:12 PM Will check again in 16 seconds.
05:12 PM Checking if deployment succeeded.
05:12 PM Deployment successful.
05:12 PM Checking if updated app version is serving.
05:13 PM Completed update of app: APP_NAME