There have been plenty of females showing an interest though, two unringed birds and two ringed Scottish females. Blue FS (Loch Ness) and White UR (Aberdeenshire), both 2010 birds, showed varying degrees of pair bonding as did the unringed birds.
He seems to have formed a fairly stable bond with a fifth female however who is also ringed. Blue 12 is yet another 2010 bird but this time from Rutland - she's actually the previous female's niece, their mothers being sisters.
Blue 12 was also spotted on the Dyfi several times last year as a two tear old, clearly prospecting for future nest sites and males. Interestingly, she was spotted at Rutland Water last year also and was first sighted in the UK this year at Rutland on April 27th, three days before being sighted on the Dyfi.