There are rumors that LR 6 is due out soon, perhaps as early as this month, and that LR 6 will have face recognition. The most recent rumors are supposedly based on product-detail pages accidentally published to Amazon Japan and other online retailers. (I give a little more credence to these most recent rumors, since it's a not uncommon mistake for a vendor to upload product details into an online retailer and then accidentally enable that product to go live prematurely before its release date. Adobe has done that before. But they are nevertheless rumors -- Adobe never announces its intentions.)
LR 5 had face recognition partially implemented but never finished and made available to users. Since LR has long had the ability to import from PSE catalogs, there's a reasonable chance that LR 6 will be able to import the PSE person tags. (But I wouldn't bet huge amounts of money on it, given Adobe's past track record in dealing with metadata between different apps.)
LR 5 doesn't support person tags in any form, so if you wanted to convert your PSE person tags to LR 5's keyword tags, you'd need to use a tool like the free Exiftool, which has a pretty steep learning curve. In the process, you'd lose the association between the tags and the particular rectangular face regions in the pics.
So I suggest you consider waiting for 1-2 months before converting your data to see LR 6's capabilities.