It seems to take strengths from Google's email aggregation prowess + Mailbox-like functionality + Google Now integration. A smart play but yeah it's going to look very derivative in light of how awesome Mailbox already is at tackling the majority of the issues with email maintenance.
Yeah, but it's possible many folks trust Google and don't trust Dropbox (or haven't even heard of Mailbox) so it's interesting for Google to access that untapped market.
