The Catholic Encyclopedia has it that majority of theologians, including St. Thomas Aquinas, hold canonization infallibly states a person is in Heaven, while with beatification it is generally agreed this is not a certainty. According to Wikipedia, in the current practice the feast of a Saint can be celebrated anywhere and parishes can be consecrated in his honor, while for a Blessed the feast is restricted to certain locations such as his home diocese, and usually parishes cannot be named after him.
Catholic Encyclopedia, Beatification and Canonization:
Is the pope infallible in issuing a decree of canonization? Most theologians answer in the affirmative. It is the opinion of St. Antoninus, Melchior Cano, Suarez, Bellarmine, Bañez, Vasquez, and, among the canonists, of Gonzales Tellez, Fagnanus, Schmalzgrüber, Barbosa, Reiffenstül, Covarruvias (Variar. resol., I, x, no 13), Albitius (De Inconstantiâ in fide, xi, no 205), Petra (Comm. in Const. Apost., I, in notes to Const. I, Alex., III, no 17 sqq.), Joannes a S. Thomâ (on II-II, Q. I, disp. 9, a. 2), Silvester (Summa, s.v. Canonizatio), Del Bene (De Officio Inquisit. II, dub. 253), and many others. In Quodlib. IX, a. 16, St. Thomas says: “Since the honour we pay the saints is in a certain sense a profession of faith, i.e., a belief in the glory of the Saints [quâ sanctorum gloriam credimus] we must piously believe that in this matter also the judgment of the Church is not liable to error.”
Canonists and theologians generally deny the infallible character of decrees of beatification, whether formal or equivalent, since it is always a permission, not a command; while it leads to canonization, it is not the last step. Moreover, in most cases, the cultus permitted by beatification, is restricted to a determined province, city, or religious body (Benedict XIV, op. cit., I, xlii). Some, however, have thought otherwise (Arriaga, Theol., V, disp. 7, p. 6; Amicus, Theol., IV, disp. 7, p. 4, no 98; Turrianus on II-II, V, disp. 17, no 6; Del Bene, De S. Inquisit. II, dub. 254).
Wikipedia, Canonization, Roman Catholic procedure since 1983:
This allows beatification, giving the venerable the new title “Blessed” (abbreviated “Bl.”) or, in Latin, Beatus or Beata. A feast day will be designated, but its observance is normally restricted to the Blessed’s home diocese, to certain locations associated with him or her, and/or to the churches or houses of the blessed’s religious order, if they belonged to one. Parishes may not normally be named in honor of a Blessed.
The saint is assigned a feast day which may be celebrated anywhere within the Catholic Church, although it may or may not appear on the general calendar or local calendars as an obligatory feast, parish churches may be built in his or her honor, and the faithful may freely and without restriction celebrate and honor the saint.