there is currently no IP obfuscation, this will however also be addressed in the future with the i2p integration
IP obfuscation will be addressed but it is far less of an issue with Monero than other coins, as I explained in the quoted post below (the context was sites such as blockchain.info tracking IP address sources for transactions). A side benefit of anonymizing the
blockchain (after all just a bunch of transactions) with each user trustlessly mixing his own transactions is that you also to a large extent anonymize against monitoring at the
transaction level as well.
The other issue not addressed below is leaking that fact that you are using Monero at all. Some may wish to keep that private (or at least not linked to your IP address) for various reasons.
Cryptonote blocks are also relayed by nodes with IP addresses, and block explorers could report them if they like. No difference here.
There is a difference. You can report IP addresses but those IP addresses are much harder to link to anything useful on the blockchain. You can't for example find transactions that paid to or from a known address and then look for the IPs associated with those transactions. You likewise can't trace the flow of funds to earlier or later transactions and look for IP addresses associated with those. Nor can you go in the other direction and take a known IP and associate addresses to it (even if imperfectly).
The only useful things you can do with these p2p spying techniques is find an IP associated with
a particular tranasction if you already know the transaction you are looking for, or find
transactions associated with an IP, but in the latter case those transactions are largely opaque (can't be traced or tied to an address, and the amount is only visible with ambiguity). That is a window of vulnerability but a much narrower one than typically exists for Bitcoin.