June 2002:  It has been brought to my attention that the above information is out of date as the "Brewers & Maltsters Guild's" page (malsters.html) and their excellent article/lobby document on the unfavourable taxation regime endured by smaller brewers (excise.html) are no longer hosted on the Dublin Brewing website (possibly they were posted there as a founder of "The Brewers’ and Maltsters’ Guild" worked as Head Brewer at the Dublin Brewing Co. from Nov 1996 to May 2000).   Unfortunately I have been unable to find them anywhere else.  The Appendix 1 referred to is now The History of Brewing in Dublin which states, "In 1949, Findlater's brewery near Mountjoy Square finally closed down, leaving Guinness as the only brewer in Dublin."
March 2004: Article found: http://www.beb.ie/downloads/IrishMicroBreweryExciseProposal.doc 12 pages - worth a read both for proposals and Dublin brewing history. 

Brief History of the Irish Microbrewing Industry

1982-83
Dempsey’s and Harty’s, two ‘real’ ale microbreweries opened and closed shortly thereafter in Dublin and Blessington, Co. Wicklow.

1995
Opening of Biddy Early's in Inagh, Co. Clare (Brewpub)
Opening of the Irish Brewing Co. in Newbridge, Co. Kildare (Microbrewery)

1996
Opening of The Porterhouse Brewing Co. in Dublin (Brewpub)
Opening of The Dublin Brewing Co. in Dublin (Microbrewery)

1997
Opening of The Celtic Brewing Co. in Enfield, Co. Meath (Microbrewery)

1998
Opening of Carlow Craft Brewery in Carlow (Microbrewery)
Opening of Dwan’s Microbrewery in Thurles, Co. Tipperary (Microbrewery)
Opening of Maguire’s Masterbrewers in Dublin (Brewpub) (Dec. '98)
Opening of Franciscan Well Brewery in Cork (Microbrewery) (Dec. '98)

Dwan - Tipperary Brewing Co., Thurles, Co. Tipperary,
Tel: (0504) 26007

Article on the Irish Craft Brewers Network (from http://archives.tcm.ie/businesspost/2002/11/17/story331602.asp)

"The ICBN craft breweries are: Porterhouse Brewing Company in Dublin, the Celtic Brewing Company in Enfield, Co Meath, Carlow Brewing, the Biddy Early Brewery in Co Clare, Irish Brewing Company, Franciscan Well microbrewery in Cork, Dwan's Brewery in Tipperary, Messrs Maguires in Dublin, the Balbriggan Brewing Company, and the Kinsale Brewing Company."

Members of the Brewers & Maltsters Guild of Ireland 
(from http://www.beb.ie/downloads/IrishMicroBreweryExciseProposal.doc)

"Dublin Brewing Company, Irish Brewing Company, The Porterhouse Brewing Company, Celtic Brewing Company, 
Dwan's Brewery, Bar & Restaurant, Carlow Craft Brewers, The Biddy Early Brewery, The Franciscan Well Microbrewery, The Balbriggan Brewing Company"

Other Irish brewers...

An enthusiastic site devoted to beer called "Beer is my Life!"

Of particular interest to us are the lists and details it contains on all Irish beer:

Breweries in Northern Ireland and Breweries in the Republic of Ireland