Nielsen Wire:
>When asked whether they used other connected devices more often or less often since purchasing a tablet, 35 percent of tablet owners who also owned a desktop computer reported using their desktop less often or not at all, while 32 percent of those who also owned laptops, said they used their laptop less often or never since acquiring a tablet. Twenty-seven percent of those who also own eReaders said they use their eReader less often or not at all – the same percentage as those who also own portable media players. One-in-four tablet owners who own portable games consoles are using those devices less often, if at all, since purchasing a tablet.

I have noticed this with my usage. My wife though — she seems unchanged.