Fantasy Flight Games has announced that conversion kits for Mansions of Madness 1st edition are now avalible on their website.
PDFs of second edition Investigator Cards, Monster Tokens, and Unique Item Cards can now be downloaded for free from the Fantasy Flight website under the support section of the Mansions of Madness page. According to Famtasy Flight, hese will allow you to convert your 1st edition of Mansions of Madness.
This is, however, a somewhat massive DIY project, particularly the tokens. This PDF contains 37 tokens (12 pages) which will need to be printed, cut out and made to be token like. If you under take this project, please let us know and share your results and any tips with us.