This might be an obvious point to many SEOs but Pierre Far from Google clarified that if you have specific landing pages for the same product but targeting different languages/countries, you can change the title tag of the page without concern.
Pierre Far from Google posted this on Google+ saying:
In my last webmaster office hours hangout I got an interesting question: When a webmaster uses rel-alternate-hreflang annotations to mark up a cluster of equivalent pages that target different language-country combinations, can the titles be different for each country?The answer is yes, use a title that makes sense for your users and your site.
I go more into detail about how to handle these specialized annotations over here.
Pierre Far then gives some more examples of how this applies on Google+.
Forum discussion at Google+.

Comments:
mamun
08/03/2012 11:38 am
Google+ is not complicated to understand. Getting more idea what i had. No tenson!! SEO Progress is here to welcome you all to see the offer for you people to get the best SEO results with 100% gaurantee. http://www.seoprogress.net/
Jogos de Estrategia
08/08/2012 05:48 pm
This is amazing news! I target same niche in 2 different countries, and I found many problems by translating/making a different landing page for the other country (it just wouldn't rank that well). Now maybe I found a solution! Many thanks, Jeremy from http://sojogosgratis.pt