The subject of your question seemed to be convergent with the matter of Today's thought of the day on BBC Radio4 - media ethics, limits and scope of passion / pain / sufference situations displayed on screens and other public performances. 
 
It is an eternal never ended question that often  hides more complex questions about the need of balanced controls of media, educational and scientific  processes and the technologies used within such processes. These are rarely neutral and independent and can be easily abused and falsified.  The problem is perceived with special sensitiveness  among right-members of society and by victims of miscarriages of justice or anti-social behaviours whereas on the opposite end of the spectrum people tend to react enthustiastically to every new-fangled thing. 
 
I personally believe illegal uses and abuses, exposure as well as distorsion and falsifications of others' voices, images, thoughts and identity's representation must be  restlessly prosecuted and sanctioned - not only because of data protection violations but because these can be serious crimes that violate basic human rights in particular contexts. 
 
I have been experimenting using and studying the matter in several contexts, often falling myself victim of very interesting, exciting, motivating or annoying, frustrating or boring situations so I gradually learned to emotionally detach myself from the uses of information and concentrate on the design instead.  
 
I designed and developed pioneering  educational and information e-services between 1997 and 2007. 
My findings on the specific point of your question were that (very sadly considered my own investments and expectations in the sector) there was no general business justification for screen sharing and co browsing for continuous professional development or  corporate training - because of the very high costs, expertise and standardisation of technologies and infrastructure required to achieve acceptable levels of desired learning / change in a often very limited time. 
 
Short structured istructional documents with clear infographics or pertinent screenshots on one side or video recordings of structured lectures or presentations on the other side worked much better but became rapidly obsolete in the end-users general daily information diet, so challenged by "extreme" constructivist and collaborative formulas. 
 
With screen sharing or co-browsing most of the people enter a lurking / entertainment mode whilst the more active members of the group tend to assume a showing off posture: the combined effect can be extremely motivating and engaging in terms of attention but completely detrimental for the educational scopes. In other terms, there is a potential increase of fun without any learning. That means in the short term you can have an excellent appraisal of your productions and processes or initiatives for funding projects or publicity but you are simply giving up your business justification as an educational institution. It may be the way for universities to approach or enter the privatisation age? Sorry if I am indulging here using your question for my own reflections on other matter. 
 
Anyway, I reached similar conclusions about use of co-browsing in live reference / enquiries services  though with some evidences of effectiveness in specific contexts (intranet applications / private clouds).
 
I did not investigate effectiveness of cobrowing or scrren casting within schools / universities classes but I would be very careful in experimenting them  because they may end in nothing more than legitimate "spying conducts" that are inevitably promoted by the so called consumerization of IT. 
 
Thanks for having given me the opportunity to add something to my article "The missing business case: rise and fall of an information literacy training programme" (accessible from my own website page publications). As many know it has been rejected by the Editor of the special issue of Library Trends on information literacy and I am not going to resubmit it to other Journals having other priorities at present but I may do it in another ten or twenty years :) 
 
Regards


Brunella Longo
Information Management Adviser, Prince2 Practitioner, Independent Scholar
brunellalongo.co.uk - 7 New College Court - London NW3 5EX
T +44 (0)2077229184  - M +44 (0)7549921488 - http://www.brunellalongo.co.uk
email: bl at brunellalongo.co.uk | brunella.longo at yahoo.com