I doubt I can say anything new, but it bears recapping the likely way to get to a true A's Championship Team.
Barring either a random superstar occurrence among MiLB A's players, or a potential superstar acquisition abroad (the way they came to possibly such a signing with Cespedes), the A's have very few chances at superstar players, under their current management policy. The general reason for such an assertion is that the A's player acquisition (through Draft, international signing, FA signings, or trades) does not seem planned farther than for the next year. What is called the "window of opportunity" for the Team is based on a tactical plan to introduce existing prospects to the Majors team, rather than on a strategic plan to acquire superstar-level Prospects through Draft or initial signing.
From a management theory perspective, that is an indication of poor strategic planning, which would be a consequence of inconsistent ownership attitudes and/or top management inability for Strategic Planning - not too alarming, since it is a rather common failing in most management teams within any type of organizations - what is most common is "crisis management."
Since the above deficiency cannot be remedied without some fundamental organizational changes, the next best alternate approach is to do as good a job as possible to prepare for, preferably, all of the four kinds of player acquisition that we know. Without believing in blind luck, the few ways to develop player resources that can be parleyed into "superstars" are either to spend money (that is for international or FA signings) - which can be done with increased game attendance, or to have a large trade-able pool of "as-good-as-possible" players.
Without depending on game attendance and out of pocket cash outlays, superior players can either appear internally (probably via good chancy Draft signings - like in the case of Addison Russell) within the A's own organization, or a relatively large number of lower-level players can be traded for Top Prospects (a hazardous approach), or a developed high-quality player can be traded away for promising Top Prospects (what the A's tried last season, netting Parker and promising youngsters like Cole).
Regrettably, the A's cannot usually invest money into true superstars, via signing of foreign players or FAs. So the key to franchise development seems to be a conscientious Draft approach plus a far-looking lower-level Prospect trading process. (Please note the use of this word - it cannot be a knee-jerk activity). As an example, the second A's Oakland dynasty superstars were drafted, generating the famous three consecutive Rookies of the Year - Canseco, MacGuire, and Weiss. However, that happened because the A's had low win records in the early 80's, allowing them top Draft picks. By happenstance, the A's got a high pick last year, netting Russell, though having a good winning record prevents them from bunching up several high picks together.
In 2013 the A's have another Draft chance: they have five picks within the first 106 players, though the first A's pick comes at #26, so there is no chance of landing a Top 20 prospect. Thus, unless they can get a "sleeper", the A's can only hope, again, to fill up their Minors with decent players, not ranked as potential Superstars, but who could be eventually traded for a Myers-type superstar.
This is the low-down. There is no magic, otherwise. Rarely just-good players can win a Championship; usually it takes one or two superstars as pitchers, and another one or two as field players. Hoping for superstar level for Anderson and Cespedes, there is still a need for another one. That is why several AN-ers have expressed the thought-hope that Billy is gearing up for a blockbuster trade, to add a superstar to the current run of good rookies. It would mean a top balancing act - to garner a championable roster without going through a period of sub .500 win years to produce top draft picks! That is why a trade for Myers was such an intriguing idea, though personally I believe that a superstar pitcher would be more of a help than a good bat, at this point. Last October, the A's had to defeat Verlander twice - and they did not have a SP to do that.