Speaking to Famitsu, a Sony Computer Entertainment representative said, "We're currently not considering changes akin to North America. However we would like to react flexibly with the market." IGN also sought out some anecdotal evidence by checking a few Tokyo game shops, finding that both the 20 GB and 60 GB were in stock. Interestingly enough, the 60 GB used model is the same price as the 20 GB new model at 49,800 yen.
Interestingly, Sony UK has given a similar company line, telling CVG, "We'll continue to monitor demand for the 20GB model ... which will be factored into any future Euro launch plans." Of course, the 20GB model has never been in Europe anyways, so the chances of them bringing the second SKU in down the road are slim to none.
[Update: Fixed image.]