Another worry for DC Nodes. http://thehackernews.com/search/label/hacking%20news Basically anything(well most methods) that can attack tor can attack any node system.
Do you mean a Monero node that broadcasts a transaction can be easily unmasked? Sounds bad.
It reveals very little useful information other than that the the IP transmitting it is a Monero user. Neither inputs nor outputs of such a transaction can be identified in a useful way. The opaqueness of the blockchain and the flow of coins between users does not depend on hiding network traffic nor on nodes.
This puts Monero in a relatively good position given that enforcing privacy at the network level looks increasingly difficult to potentially impossible (outside of somewhat low tech measures such as wardriving).
Of course we have said we plan to integrate i2p and that will help somewhat (the goal being to not disclose that a particular IP is using Monero at all), but even if i2p is completely compromised the content of your transactions can still not be uncovered, only the fact that you are making them.
Investing 1% more of my wealth to XMR at these prices is quite many coins 
