As with any interesting question this one can also only be answered: Yes and No. It is clear that any web based project can not ignore the elephant in the room that is Google and its vast amounts of tools and services. But the last months have shown that not all Google tools can be used for eParticipation or have gained any real traction among mainstream users.
Google services, which can be integrated into third party websites, like search, the single-sign-on mechanism friend connect, or Google Maps have shown to be very useful if integrated into eParticipation platforms, while consumer facing products like Google Buzz or Wave have flopped with the general audience.
In November 2009, shortly after the launch of Google Wave I tried to summaries its potential uses for eParticipation as discussed by many eParticipation experts making use of the tool itself. Since then there was little to no activity on that specific Wave and a look at the Google Wave development blog indicates that the development of the tool has slowed down considerably. There are still many new Waves published each day but many of those are still related to testing the tool or have almost no activity in them. Google Buzz launched to major buzz (pun intended) earlier this year but has more or less developed into a place for forwarded Twitter posts.
Google Services aimed at programmers or for integration into third party sites however are not only widely used but have also been implemented as useful additions to eParticipation sites. Google Maps is the go-to provider for geo-data and has been used in countless eParticipation projects. Some projects have been completely built on Google Sites and Google custom search is a powerful way to implement search tools on websites. Furthermore some projects have started to look into Google Appengine to host their sites or are even involved in the Google Summer of Code effort. The company also provides many great APIs and little helper tools which are useful for many eParticipation sites (An example would be the SocialGraph API).
After this short overview of the topic the question remains: Could it be that Google is great at building infrastructures which others can use to build great sites and webapps and just fails in consumer facing products? Of course there are examples like Gmail or the Android OS which show that the big G is capable of building great user experiences but there seems to be something to this assessment.