I experienced difficulties obtaining HDD replacement in a timely manner. I ordered a Seagate 320Gb ACE drive on Aug 01, 2007 and supplier (Span) was then quoting Aug 10 availability. Supplier subsequently contacted me when their re-stocking date slipped; by 2nd week in September they still had no indication from manufacturer as to when new supplies would be forthcoming. I subsequently switched supplier to Komplett as they were one of the very few still showing stock of Seagate ACE drives (but I had to settle for 400Gb disk as they too were out of stock of 320Gb drives).
Komplett despatched disk right away and I received it within a couple of working days or so. I've no problem with Span being unable to meet my order - they informed me there were stock problems and, in any event, problem is down to Seagate which affects all suppliers.
Seagate recently announced that they were to cease manufacture of IDE drives by end of 2007 - I suspect current lack of stock by many UK suppliers reflects some 'winding down' of manufacturing process in advance. I also understand at least one other disk manufacturer has also announced intention to cease supply of IDE drives.
The above situation will clearly make it harder for owners of existing generation of Sky+ boxes to readily source HDD upgrades and also, potentially, replacement standard 160Gb drives. Once the disk becomes obsolete from leading manufacturers the price may well rise as economies of scale no longer apply. At some point Sky+ users requiring replacement HDD's may well be faced with either replacing the Sky+ box or adding an IDE / SATA converter board to enable current generation of HDD's to be used instead. There's not that much room in the Sky+ boxes and I suspect many would find the prospect of fitting a SATA drive messy and / or expensive.
I wonder if Sky have any plans to ensure a decent supply of IDE drives is maintained.