A word regarding the dissolution of marriage:
I have not heard that an unconsummated marriage can be dissolved. However, I do know that a marriage can be dissolved in some select circumstances. First, some definitions:
Valid marriage - a marriage in which there is a marriage covenant. In order for a marriage to be valid, it must occur between one man and one woman, to the exclusion of all others, with an intent to be open to new life, a desire to remain faithful until death, free consent of will, and in accordance with Church laws (if at least one individual is Catholic). A marriage cannot occur between close relatives, underage persons, or in situations where permanent inability to have intercourse exists.
Natural marriage - marriage where at least one party is not baptized. This may be a civil or a religious ceremony. Natural marriages are considered de facto valid by the Church.
Sacramental marriage - marriage where both parties are baptized. If one or both parties are not baptized at the time of the marriage, but are baptized subsequently, no convalidation is required (assuming they are already validly married); Baptism alone relegates the marriage to sacramental status.
Only valid, natural marriages can be dissolved. Sacramental marriages may be declared invalid, but they cannot be dissolved.
In the case of two non-baptized parties, if the marriage ends, the bishop can dissolve the marriage. This is called the Pauline Privilege. It is usually restricted to cases in which one individual desires Baptism in the Catholic Church and desires to contract a valid marriage with a Catholic.
In the case of one baptized and one non-baptized party, if the marriage ends and it is not the fault of the baptized party, the Pope can dissolve the marriage. This is called the Petrine Privilege, or the Favour of the Faith.
Other than these circumstances, it is not possible for a marriage to be formally “dissolved” to the best of my knowledge; it may only be declared valid or invalid.
In the case of something that can be easily proven on paper (e.g. consanguinity, prior bond of marriage, marriage outside the Church without a dispensation, etc.) only paperwork is necessary to declare the marriage invalid. This is often called “documentary procedure” and takes usually only a few weeks.
In the case of something more nebulous (e.g. lack of understanding of the nature of marriage, intent not to have children, infidelity, etc.) a formal nullity trial is required. Both the petitioner and the respondent (if he/she agrees) will be interviewed, as will witnesses. Additional documentation may be required. The Church’s goal is to have a formal nullity trial concluded within 18 months, although this is not a firm deadline.