I love Swarovskis and adore their bicones - they feature in so many things I do these days in one way, shape or form - but it is shortly going to be replaced.
The new bead - the Xilion cut (reference 5328) - will over the coming months replace the 5301 bicone bead. From what I've read, the Xilion has alternating size facets and more cuts which will give better light reflection and it also seems it will be a littler rounder around the middle than the standard bicone. So far as I understand it, all the bicone shapes are to be replaced with the exception of the 2.5mm.
If you can't bear to be without the traditional bicone, hurry and buy them now as once the transition period has gone (June to September this year) once stocks run out you won't be able to get the current shape any more...apparently.