Probably not, but there have been a few straws in the wind recently -- a few more and we may be able to declare a trend.
I noted here a few weeks back that Wal-Mart was decreasing its shelf space allocated to private label soft drinks, in favor of Cadbury Schweppes' products (much to the discomfort of Cotts). There is also the case of Sears, which is considering selling some of its powerful private labels through other retailers. And now we have Britain's Marks & Spencer, which has long sold only its own brands, but is considering introducing brand names onto its shelves.
The trend toward increasing market share for private label is so long established and so strong, that it seems impossible that it will ever stop. But everything stops somewhere (or so we all believe). Whether that point has been reached for private label is impossible to know (and a weak economy seems an unlikely time for a slowdown in private label), but a few more straws and maybe I'll believe.