As per my question above... does the data usage that came into existence in ICS count uploads as well as downloads?
Yes, there's an API for that (the class is
As you can see below, it offers both Rx and Tx bytes in total, only accounting mobile or per app (added in API level 14, note that with an equal UID count as one). This is an excerpt, see the link below for all methods.
Implementation for the "data usage" view: here
PS: The carriers also count UDP traffic that just leaves their end but never arrives, such as rtp streams where the phone loses the carrier but the whole video gets streamed anyway.