Aqui está uma maneira:
SELECT
sysobjects.name AS trigger_name
,USER_NAME(sysobjects.uid) AS trigger_owner
,s.name AS table_schema
,OBJECT_NAME(parent_obj) AS table_name
,OBJECTPROPERTY( id, 'ExecIsUpdateTrigger') AS isupdate
,OBJECTPROPERTY( id, 'ExecIsDeleteTrigger') AS isdelete
,OBJECTPROPERTY( id, 'ExecIsInsertTrigger') AS isinsert
,OBJECTPROPERTY( id, 'ExecIsAfterTrigger') AS isafter
,OBJECTPROPERTY( id, 'ExecIsInsteadOfTrigger') AS isinsteadof
,OBJECTPROPERTY(id, 'ExecIsTriggerDisabled') AS [disabled]
FROM sysobjects
INNER JOIN sysusers
ON sysobjects.uid = sysusers.uid
INNER JOIN sys.tables t
ON sysobjects.parent_obj = t.object_id
INNER JOIN sys.schemas s
ON t.schema_id = s.schema_id
WHERE sysobjects.type = 'TR'
EDIT : junção comentada aos sysusers para que a consulta funcione no AdventureWorks2008.
SELECT
sysobjects.name AS trigger_name
,USER_NAME(sysobjects.uid) AS trigger_owner
,s.name AS table_schema
,OBJECT_NAME(parent_obj) AS table_name
,OBJECTPROPERTY( id, 'ExecIsUpdateTrigger') AS isupdate
,OBJECTPROPERTY( id, 'ExecIsDeleteTrigger') AS isdelete
,OBJECTPROPERTY( id, 'ExecIsInsertTrigger') AS isinsert
,OBJECTPROPERTY( id, 'ExecIsAfterTrigger') AS isafter
,OBJECTPROPERTY( id, 'ExecIsInsteadOfTrigger') AS isinsteadof
,OBJECTPROPERTY(id, 'ExecIsTriggerDisabled') AS [disabled]
FROM sysobjects
/*
INNER JOIN sysusers
ON sysobjects.uid = sysusers.uid
*/
INNER JOIN sys.tables t
ON sysobjects.parent_obj = t.object_id
INNER JOIN sys.schemas s
ON t.schema_id = s.schema_id
WHERE sysobjects.type = 'TR'
Edição 2 : para SQL 2000
SELECT
o.name AS trigger_name
,'x' AS trigger_owner
/*USER_NAME(o.uid)*/
,s.name AS table_schema
,OBJECT_NAME(o.parent_obj) AS table_name
,OBJECTPROPERTY(o.id, 'ExecIsUpdateTrigger') AS isupdate
,OBJECTPROPERTY(o.id, 'ExecIsDeleteTrigger') AS isdelete
,OBJECTPROPERTY(o.id, 'ExecIsInsertTrigger') AS isinsert
,OBJECTPROPERTY(o.id, 'ExecIsAfterTrigger') AS isafter
,OBJECTPROPERTY(o.id, 'ExecIsInsteadOfTrigger') AS isinsteadof
,OBJECTPROPERTY(o.id, 'ExecIsTriggerDisabled') AS [disabled]
FROM sysobjects AS o
/*
INNER JOIN sysusers
ON sysobjects.uid = sysusers.uid
*/
INNER JOIN sysobjects AS o2
ON o.parent_obj = o2.id
INNER JOIN sysusers AS s
ON o2.uid = s.uid
WHERE o.type = 'TR'