Is there one Generation Y?

I just skimmed through the ACRL 2009 strategic thinking guide. This is interesting input for my present work, although some points are related to the situation in America. I did find three interesting observations regarding students:
" • Increasingly, multiple generations make up the student enrollment at most colleges (either virtually or physically). This trend is likely to persist as the unemployed return to retool and reskill."
This combines nicely with the ideas regarding Life Long Learning on this side of the Atlantic...

"• We are all “becoming” Generation Y (also known as the Net or Millennial generation). New research shows that increased access to sophisticated technological social tools and increased connectivity via smart phones, laptops, and other handheld devices is changing the behavior of several generations; other generations are taking on the characteristics of Generation Y. Frequently cited generational differences are beginning to blur."
I like the 'we' in this quote. Does this mean that this is not a generation as in an age group, but rather a portion of the population? This would connect nicely with the findings that there are large differences within the young age group regarding technology uptake and attitude. This also matches the findings that older generations (e.g. the old X gen) are taking on social networking, gaming, twittering etc. more and more seriously...

"• The gadget-savvy Millennial students do not fully comprehend the complex networked
information world: “students may have confidence because they are unaware of the complexities involved [in using the Internet effectively] or just because they have grown up with technology. This potential gap between actual and perceived skills and literacy is important to understand and factor into strategies for teaching and learning at the institution.”
OK, I interpret this as follows, but correct me if I'm wrong: they think they are smart, but they do need some training in Information Literacy. This is a point which does keep on popping up.