In an interview with Marketing Week (requires a painful registration process to access) Sega Europe's marketing director Jon Rooke confirmed that the company is looking into possibly re-releasing Shenmue 1 and 2 in some shape given the interest Shenmue 3 has garnered. As you'd suspect there are no details on what platforms might be considered. Hopefully any exclusivity deal Microsoft held for Shenmue 2 has expired by now.
Thanks, VG247.