Have an existing application at http://pad-katello.rhcloud.com/ that I was unable to restart after the upgrade a few weeks ago.  It appears from discussion on #openshift that node is unable to find mongo.  

I did a git push repeatedly in attempts to see if I could get the app to come back online but only saw this in the logs:

Tue Jun 18 2013 11:58:17 GMT-0400 (EDT): Stopping application 'pad' ...
Tue Jun 18 2013 11:58:18 GMT-0400 (EDT): Stopped Node application 'pad'
Tue Jun 18 2013 12:02:13 GMT-0400 (EDT): Starting application 'pad' ...
npm info it worked if it ends with ok
npm info using npm@1.1.37
npm info using node@v0.6.20
npm info prestart etherpad-lite@1.0.0
npm info start etherpad-lite@1.0.0

> etherpad-lite@1.0.0 start /var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo
> node server.js

[2013-06-18 12:02:17.696] [WARN] console - Can't get git version for server header
ENOENT, no such file or directory '/var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo/.git/HEAD'
[2013-06-18 12:02:17.701] [INFO] console - Report bugs at https://github.com/Pita/etherpad-lite/issues

module.js:337
    throw new Error("Cannot find module '" + request + "'");
          ^
Error: Cannot find module 'mongodb'
    at Function._resolveFilename (module.js:337:11)
    at Function._load (module.js:279:25)
    at Module.require (module.js:359:17)
    at require (module.js:375:17)
    at new MongoKeyValue (/var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo/node_modules/ueberDB/mongodb_db.js:68:19)
    at [object Object].init (/var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo/node_modules/ueberDB/mongodb_db.js:34:18)
    at [object Object].init (/var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo/node_modules/ueberDB/CacheAndBufferLayer.js:108:18)
    at [object Object].init (/var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo/node_modules/ueberDB/CloneAndAtomicLayer.js:48:11)
    at Object.init (/var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo/node/db/DB.js:41:6)
    at /var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo/node/server.js:74:8
npm info etherpad-lite@1.0.0 Failed to exec start script
npm ERR! etherpad-lite@1.0.0 start: `node server.js`
npm ERR! `sh "-c" "node server.js"` failed with 1
npm ERR! 
npm ERR! Failed at the etherpad-lite@1.0.0 start script.
npm ERR! This is most likely a problem with the etherpad-lite package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     node server.js
npm ERR! You can get their info via:
npm ERR!     npm owner ls etherpad-lite
npm ERR! There is likely additional logging output above.

npm ERR! System Linux 2.6.32-358.10.1.1.el6.x86_64
npm ERR! command "node" "/usr/bin/npm" "start" "-d"
npm ERR! cwd /var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo
npm ERR! node -v v0.6.20
npm ERR! npm -v 1.1.37
npm ERR! code ELIFECYCLE
npm ERR! message etherpad-lite@1.0.0 start: `node server.js`
npm ERR! message `sh "-c" "node server.js"` failed with 1
npm ERR! 
npm ERR! Additional logging details can be found in:
npm ERR!     /var/lib/openshift/31a670cefa974de0848026df36f63f96/app-root/runtime/repo/npm-debug.log
npm ERR! not ok code undefined
npm ERR! not ok code 1