Hi Natali
I just tried this for my Marketo account. Expand all the landing pages and forms in your Design Studio. Once the whole list is there, simple do Select All (ctrl+A in Win / cmd+A in Mac) and paste that in the notepad. Now from your notepad, paste this in Excel doc. Here, you have have to remove extra rows and columns.
This is the only solution that we presently have in Marketo to get the listof assets/lists/programs.
Regards
Alok