We've completed initial testing on our OUI/MMUI Store Framework Exporter.
There's 4 unique modules in here all for 4.x compiled:
1. MMUI Framework Exporter
2. OUI Framework Exporter
Both of these work in the same way, install them, go to Stores - StoreName - Utilities - Export and you'll see a new Export Framework option. Then go to a PR6 or MMUI PR7 and install the Framework.
3. Catalog Exporter
4. Order Exporter
Both of them create XML exports and you use the XML importer in 5.5 to upload the file and it imports.
It's important to note that specifically if you're using OUI, this Framework exporter does NOT attempt to parse the OUI tokens. This tool is not designed to make a one click 4.x OUI export/import into 5.5 that gets you all the way to a live store, but instead the goal is to get you 70 - 90% of the way there and save you time (and therefore money) in completing the final steps.
You'll need to look at your Dev site once you've installed the Framework and go look for all the un-rendered OUI tokens and replace them with something meaningful in the 5.5 universe.
Click here to download the tools from our support suite.