Several comments/enquiries about the impact of luxury cuvees on the quality of standard wines have been received. There are debates about this very thing with Rhone wines. My own feeling is that it can certainly be true that prestige wines are made to the detriment of the regular bottling, it is not always so.
Before elaborating, the other way to approach multiple cuvees is that used by most Bordelais: the best grapes make the main wine; anything deemed not quite up to standard goes into a second wine and so on. The Rhone works the other way round (although it must be said that inferior grapes are sold off to cooperatives, negociants or turned into industrial alcohol, at least they are if they come from any self respecting grower!).
For example, in a vintage such as 2002, Rhone wines were not all good (an understatement in many cases). However, when I visited Raymond Usseglio, all ready to tell him that I would see him the following year without placing an order for the 2002s, he produced two cuvees, one early bottled for the American market (before Parker released his verdict?) and one later bottled including the old vine grapes that usually go into "Imperiale". The difference was phenomenal - the second wine really was very good, not just for the vintage although it was difficult to assess whether this was the result of the later bottling or the inclusion of old vine Grenache (rather unfortunate in this particular case since the vines had been planted in 1902 so this would have been it centinary year). That is an example of prestige wines potentially detracting from the standard bottle although not in actual fact (although there are some estates who still made prestige wines in 2002).
However, the flip side can be (but not necessarily is) that prestige wines are often produced in such small quantities that they would have little effect on the standard wine. Usseglio's 2007s could be cited here as the quality of the regular wine is so high that the grapes included in the prestige wines would have little effect. Indeed, the main difference between the wines is stylistic rather than qualitative.
Another example is Domaine de Mourchon which has made the Family Reserve wines in 2008 but not the Grande Reserve simply because there was a big enough harvest of first class grapes to warrant micro-cuvees of the FR wines with no apparent impact on the Tradition but to produce the GR would be to reduce the quality of the Trad. Sadly, not enough producers here (or anywhere else) have this level of integrity.