Good question and good answers. Elsegood looked great as a rookie.
I think the players who generate high hopes are often guys you hope will cover for the retirement or exit of a great player like Mortimer, Lamb or Price. History shows that they rarely live up to the pressure/expectations and it usually takes a couple of years to find a genuine replacement. This happened in 1988 (Mortimer), 1995 (Lamb) and 2004 (Price and others).
We were lucky, for example, to replace Harrigan with El Masri (better winger and equal as a goalkicker).
We all hoped Holdsworth would kick on after 2006 but it never happened. Nick Kouparitsas in 2007 was another player who generated high hopes.
I even think you could put guys like Maitua and SBW in that category because we should have been able to build a team around them. They never reached their true potential as players. You always hoped that they could become leaders - but they never did.
But if I had to name one guy, I would pick - Geordie Peats.
He was a hooker that had all the skills and he was tough too. I think he was affected by the cancer that came after 1988 premiership with Gould as coach anddefections to Ryan's Wests. He ended up fading away at Souths in the end I think - probably he was a junior there.
Special mention to Kyle White too - I talked about him another time on another forum. He was a real gun as a youngster who threw himself at the line - but never fulfilled his massive potential.