Captain, all the risk in Telstra is to the downside.
The long run up from Nov 2010 is an Elliott Wave 1. It looks stretched and needs a significant pullback. Normally Wave 2 is 61.8%, although 38.2% down to about $5 looks more realistic given the dividend flow.
That said, it's been holding up better than I expected which is probably due to all the SMSF buy and hold divvy chasers, but I expect the professionals will be distributing. Possible catalyst for a fall might be the rise in US interest rates, which if eventually flows here makes yield plays less attractive. Once it starts to fall for whatever reason, in a stock where everyone has made money, then people could sell to lock in profits, stops get hit and so it can slide more than you might expect.
Not saying it cant go up as it's a stock people will just blindly buy, but in my view any long position will continue to look stretched until a decent pullback has occurred.