Adobe Premiere & Final Cut Pro project file standard?
FCP can export an XML file that contains the basics of your sequence. Premiere can then import this and create a native project file based on the contents of that XML. I'm pretty sure Premiere can also export a similar file for import/conversion into FCP (I haven't tried though).

It's worth noting that the formats are likely to change considerably years down the line, to the extent that a later version of the same software package may not be able to open it. You're best bet is to make sure all the individual files are archived so that if you're in that situation, you can just start over with the same files.