A deacon I knew (he's in seminary for ordination now) contrasted us from the Vatican on this issue: the Vatican delegates almost anything that can be to the deacon, whereas the Orthodox tries to give him as little liturgical role as possible. The Vatican sees the deacon as a subpriest, the Orthodox as a glorified layman.
If you study the traditions overall, as well as each tradition over time, I think it's a little more complicated than simply saying the Orthodox view the deacon as a glorified layman.
My thesis research was on funeral rites, and while it seems the OO traditions have retained a special funeral rite for deacons, the EO use the layman's rite, but bury the deacon in full vestments; in the past, however, the EO also had a diaconal funeral rite, which fell out of use at some point. On the other hand, in the OO traditions, deacons don't always and everywhere get to wear clerical garb (cassocks, rasson, hats, etc.), while they do in the EO traditions. Each tradition basically has ways of indicating that deacons straddle the fence between both "worlds" (and this is one of the traditional explanations, for example, of why deacons in Syriac tradition are ordained while kneeling on one knee--one foot forward toward the altar, the other back toward the nave). I prefer this "on the fence" imagery rather than saying that deacons are "glorified laymen" or "half priests"--they have their own charism.
With regard to the Liturgy, I don't know that I'd say the Orthodox try to assign the deacon as little a role as possible; when you have a deacon, his role is pretty prominent in the Byzantine rite, for example, though not as prominent in the OO rites. But it is true that certain things are not delegated unless it's necessary. Assisting with the communing of the faithful, for example: they can assist with this, but it has to be done with a blessing, and if it can be avoided, it is. They can also read the Gospel, but this also varies among the traditions: Byzantines and Armenians will typically give this to the deacon, while Syrians reserve the Gospel almost always to the priest or bishop, EVEN if the deacon is asked to assist with Communion later. But Syriac tradition will allow the deacon to do certain things that I am not aware happen in any other tradition: there is an "emergency" rite of baptism which a deacon can administer in the absence of a priest, which includes prayers, "blessings", etc.; deacons can, in the absence of a priest, conduct funerals, offer incense (we view this as a sacrificial function, and so it can ordinarily be done only by priests), read certain priestly prayers during the Office, and complete the Liturgy if the priest should be incapacitated at some point after the epiclesis and another priest cannot be summoned to complete it. Deacons are funky creatures.
Your deacon friend was right about the RC's delegating whatever could be delegated to deacons, but he didn't go far enough IMO. Apparently, they not only delegate the distribution of Communion, but also funerals, weddings, and baptisms to laypeople (typically, but not exclusively, in "mission" territories...I've read of lay-led funerals in Europe). Basically, it seems you only need a priest for the Liturgy, for confession, and for unction--everything else can theoretically be done by Bill or Peggy as long as the bishop signs off on it.