There has been no confirmation as of yet on the system that Monster Hunter 5 will be coming to but many in the gaming business, working around Capcom and Sony have said that Sony is in talks with Capcom to try and make it happen. Monster Hunter 5 would be a huge boost for Sony in Japan and in the west as well.
Sony would also highly benefit having MH5 exclusivity over Nintendo's Switch console which has seen an increase in market shares and sales since the announcement of MHxx for the Switch.
A Monster Hunter game for the PS4 would have the benefits of graphics and power on it's side though the MH series in general has sold better on portable systems (see the 3DS' sales of MH for reference.)
Others have speculated that Capcom will Split the Monster Hunter series into it's two major parts, a home console MH franchise (including MH5, frontier and so on) and it's 'Portable' series. The portable games would remain mostly with Nintendo's portable Switch and 3ds while the home console would go to the PS4.
Out of Curiosity how many of you would like to see Monster Hunter on the PS4? With the switch being both Home and Portable would Capcom benefit having MH on the PS4 in ways other than graphically? What's your opinion?