i'd say the pressing need is integration with everything while staying in control of the content.
i don't want g+ to replace facebook, twitter and my private blog... i want it to become the tool to manage all my online presences/outlets.
example: that android image/video auto-push and later publish function is pretty cool. i would use it a lot, if i could publish uploaded media to youtube, facebook, flicker, ... from the already uploded g+ cache.
example: i find a funny webcomic... i want to publish the url on twitter with a hashtag and since it's funny, i also want it to show up on facebook (with a thumbnai!)... so i should be able to use my g+ app or the webinterface to do that. nice sideffect for google: i would also automatically publish in g+.
over time it could be, that i discover, i don't really need twitter anymore, because meanwhile most interesting people i followed on twitter also double publish via g+. i can now directly follow them on g+ only.
another problem i see with g+ is, the integration of twitter style "only short messages and urls" and the blog/journal style "long story about something" messages in one feed. i am not interested in long text when browsing my circles for news and interesting stuff. (a la browsing reddit for stupid cat images and memes) ... i want short text. so they should either create a separate feed-thingie for articles, or make reasonable small summaries (140 char has proven to work remarkably well in our short-attention-span times).
i could go on, but it all comes back to seamless integration. allright, now hire me and i tell you more...