Justin's team barely make comparisons between him and JT. Yes, he was an inspiration for the young Biebs, but his manager and Bieber both say that they speak about MJ 'every other day' in contrast to speaking about JT, what... Yearly?
Besides, JT's team have said Timberlake is still open to work with Biebs regardless of his acting career. If he was that desperate to change into 'the next JT' then why wouldn't he take up the offer anyway? He's always voiced that he wants to be 'MJ status' not grow into an actor, which Timberlake seems more than happy to be doing.
Let's not forget how Justin's performances of 'Cry Me A River' **** on Timberlake's and the fact Bieber signed with Usher because he was going to be in control of his own career, whereas JT wanted too much control over it.