An evidentiality suffix in Spanish

It is well known that many languages convey evidentiality (the modality that expresses the speaker's attitude toward the evidence for his/her statement) by using a set of suffixes or particles. Let me put an example that does not belong to Spanish. Hidatsa (a native-american language from Missouri) has a “reportative” particle to express that the speaker was given the information by someone else, but s/he does not have sufficient evidence (it is a rumor, let’s say):

(1)
wacéo wíira rackí-heó rahe
man piepe carried REPORTATIVE
“The man carried the pipe, they say”
[from Palmer 2001 Mood and Modality: 42]

Interestingly, in Spanish, the conditional suffix -ría can play this role. It is the so called Conditional de Rumor:

(2) Brittney Spears ya estaría embarazada
[literally: Brittney Spears would be pregnant already]

Notice that the suffix -ría can be a normal conditional suffix too:

(3) Brittney Spears ya estaría embarazada si se hubiera casado con su amigo

Of course, like English, Spanish has several other means to mark the evidentiality (mainly, adverbs). What is interesting in this case is that also a suffix can do this job. Sentences like (2), however, are banned by the prescriptive discourse, although they are very common, even in standard speech (especially in the press).